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Sun of Goddard Space Flight Center (GSFC) from 2000
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NASA Space Observatories Gli
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| Title |
NASA Space Observatories Glimpse Faint Afterglow of Nearby Stellar Explosion |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. Back to top [ #top ] |
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Hubble Observations Confirm
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| Title |
Hubble Observations Confirm that Planets Form from Disks Around Stars |
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The Carina Nebula: Star Birt
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| Title |
The Carina Nebula: Star Birth in the Extreme |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. In celebration of the 17th anniversary of the launch and deployment of NASA's Hubble Space Telescope, a team of astronomers is releasing one of the largest panoramic images ever taken with Hubble's cameras. READ: Junior version of this article Amazing Space Learn about this story in the Star Witness, a science newspaper available on our sister site, Amazing Space. [ http://amazing-space.stsci.edu/news/archive/2007/02/ ] It is a 50-light-year-wide view of the central region of the Carina Nebula where a maelstrom of star birth —, and death —, is taking place. This image is a mosaic of the Carina Nebula assembled from 48 frames taken with Hubble's Advanced Camera for Surveys. The Hubble images were taken in the light of neutral hydrogen during March and July 2005. Color information was added with data taken in December 2001 and March 2003 at the Cerro Tololo Inter-American Observatory in Chile. Red corresponds to sulfur, green to hydrogen, and blue to oxygen emission. |
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Los Angeles Faults
| Title |
Los Angeles Faults |
| Description |
Los Angeles, Calif., is one of the world's largest metropolitan areas with a population of about 15 million people. The urban areas mostly cover the coastal plains and lie within the inland valleys. The intervening and adjacent mountains are generally too rugged for much urban development. This is in large part because the mountains are "young," meaning they are still building (and eroding) in this seismically active (earthquake prone) region. Earthquake faults commonly lie between the mountains and the lowlands. The San Andreas fault, the largest fault in California, likewise divides the very rugged San Gabriel Mountains from the low-relief Mojave Desert, thus forming a straight topographic boundary between the top center and lower right corner of the image. We present this perspective image from NASA's Shuttle Radar Topography Mission (SRTM) with a graphic overlay that maps faults that have been active in Late Quaternary times (white lines). The fault database was provided by the U.S. Geological Survey. The Landsat image used here was acquired on May 4, 2001, about seven weeks before the summer solstice, so natural terrain shading is not particularly strong. It is also not especially apparent given a view direction (northwest) nearly parallel to the sun illumination (shadows generally fall on the backsides of mountains). Consequently, topographic shading derived from the SRTM elevation model was added to the Landsat image, with a false sun illumination from the left (southwest). This synthetic shading enhances the appearance of the topography. Size: View width 134 kilometers (83 miles), view distance 150 kilometers (93 miles) Location: 34.3 degrees North latitude, 118.4 degrees West longitude Orientation: View west-northwest, 1.8 X vertical exaggeration Image Data: Landsat Bands 3, 2+4, 1 as red, green, blue, respectively Original Data Resolution: SRTM 1 arcsecond (30 meters or 98 feet), Landsat 30 meters (98 feet) Graphic Data: Earthquake faults active in Late Quaternary times Date Acquired: February 2000 (SRTM), May 4, 2001 (Landsat). Image Courtesy SRTM Team [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://www.jpl.nasa.gov/srtm/ ] NASA/JPL/NIMA and Landsat 7 Science Team [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://landsat7.usgs.gov/ ] NASA GSFC/USGS |
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The Eskimo Nebula from the N
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| Title |
The Eskimo Nebula from the Newly Fixed Hubble |
| Explanation |
In 1787, astronomer William Herschel [ http://www.windows.umich.edu/cgi-bin/tour_def/people/enlightenment/herschel.html ] discovered the Eskimo Nebula [ http://www.seds.org/billa/twn/n2392x.html ]. From the ground, NGC 2392 resembles a person's head surrounded by a parka [ http://www.oregonlink.com/arctic/cormorant_parka.html ] hood. In 2000, just after being fixed [ http://antwrp.gsfc.nasa.gov/apod/ap000105.html ], the Hubble Space Telescope [ http://antwrp.gsfc.nasa.gov/apod/ap970306.html ] imaged the Eskimo Nebula. From space, the nebula displays gas clouds so complex they are not fully understood. The Eskimo Nebula [ http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1990ApJ...362..226O ] is clearly a planetary nebula [ http://antwrp.gsfc.nasa.gov/apod/planetary_nebulae.html ], and the gas seen above composed the outer layers of a Sun-like star only 10,000 years ago. The inner filaments visible above [ http://oposite.stsci.edu/pubinfo/pr/2000/07/pr-photos.html ] are being ejected by strong wind [ http://www-istp.gsfc.nasa.gov/Education/wsolwind.html ] of particles from the central star. The outer disk contains unusual light-year long orange filaments. The Eskimo Nebula lies about 5000 light-year [ http://www.treasure-troves.com/astro/Light-Year.html ]s away and is visible with a small telescope in the constellation [ http://www.emufarm.org/~cmbell/myth/myth.html ] of Gemini [ http://www.astro.wisc.edu/~dolan/constellations/constellations/Gemini.html ]. |
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Gamma-Ray Moon
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Gamma-Ray Moon |
| Explanation |
If you could see gamma rays [ http://antwrp.gsfc.nasa.gov/apod/ap000722.html ] - photons with a million or more times the energy of visible light - the Moon would appear brighter than the Sun! The startling notion is demonstrated by this image of the Moon from the Energetic Gamma Ray Experiment Telescope (EGRET [ http://cossc.gsfc.nasa.gov/docs/cgro/cgro/egret.html ]) in orbit on NASA's Compton Gamma Ray Observatory [ http://cossc.gsfc.nasa.gov/docs/cgro/index.html ] from April 1991 to June 2000. Then, the most sensitive instrument of its kind, even EGRET could not see the quiet Sun which is extremely faint at gamma-ray energies. So why [ http://www.aas.org/publications/baas/v28n4/aas189/abs/ S025002.html ] is the Moon bright? High energy charged particles, known as cosmic rays [ http://imagine.gsfc.nasa.gov/docs/features/topics/snr_group/ cosmic_rays.html ], constantly bombard the unprotected lunar surface generating gamma-ray photons. EGRET's gamma-ray vision [ http://cossc.gsfc.nasa.gov/docs/cgro/epo/vu/ index.html ] was not sharp enough to resolve a lunar disk or any surface features, but its sensitivity reveals the induced gamma-ray [ http://antwrp.gsfc.nasa.gov/apod/ap050331.html ] moonglow. So far unique [ http://glast.gsfc.nasa.gov/ ], the image was generated from eight exposures made during 1991-1994 and covers a roughly 40 degree wide field of view with gamma-ray intensity represented in false color. |
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The Eskimo Nebula from Hubbl
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| Title |
The Eskimo Nebula from Hubble |
| Explanation |
In 1787, astronomer William Herschel [ http://www.windows.ucar.edu/cgi-bin/tour_def/people/enlightenment/herschel.html ] discovered the Eskimo Nebula [ http://www.seds.org/billa/twn/n2392x.html ]. From the ground, NGC 2392 resembles a person's head surrounded by a parka [ http://www.oregonlink.com/arctic/cormorant_parka.html ] hood. In 2000, the Hubble Space Telescope [ http://antwrp.gsfc.nasa.gov/apod/ap021124.html ] imaged the Eskimo Nebula [ http://www.noao.edu/outreach/aop/observers/n2392.html ]. From space, the nebula displays gas clouds so complex they are not fully understood. The Eskimo Nebula [ http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1990ApJ...362..226O ] is clearly a planetary nebula [ http://antwrp.gsfc.nasa.gov/apod/planetary_nebulae.html ], and the gas seen above composed the outer layers of a Sun [ http://antwrp.gsfc.nasa.gov/apod/sun.html ]-like star only 10,000 years ago. The inner filaments visible above [ http://hubblesite.org/newscenter/newsdesk/archive/releases/2000/07/image/a ] are being ejected by strong wind [ http://www-istp.gsfc.nasa.gov/Education/wsolwind.html ] of particles from the central star. The outer disk contains unusual light-year [ http://en.wikipedia.org/wiki/Light_year ] long orange filaments. |
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Eros At Sunset
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Eros At Sunset |
| Explanation |
Gleaming in the rays of the setting sun, boulders litter the rugged surface of asteroid 433 Eros [ http://near.jhuapl.edu/eros/ ]. The brightest boulder, at the edge of the large, shadowy crater near this picture's bottom center, is about 30 meters (100 feet) across. In orbit around Eros since February 2000, the NEAR Shoemaker [ http://near.jhuapl.edu/NEAR/ ] spacecraft's camera recorded the dramatic view [ http://near.jhuapl.edu/NEAR/iod/20000821/index.html ] earlier this month from an altitude of about 50 kilometers. Eros itself orbits [ http://www.fwkc.com/encyclopedia/low/articles/o/ o018000416f.html ] the Sun with a perihelion [ http://imagine.gsfc.nasa.gov/docs/ dictionary.html#perihelion ] of 1.13 Astronomical Units [ http://imagine.gsfc.nasa.gov/docs/ask_astro/ answers/980122b.html ] (AU) and aphelion [ http://imagine.gsfc.nasa.gov/docs/ dictionary.html#aphelion ] of 1.78 AU. Part of a class of near-Earth asteroids [ http://neo.jpl.nasa.gov/neo.html ], it spends much of its time between the orbits of Mars (at 1.5 AU) and Earth (at 1 AU) ... but it wasn't always that way. Eros and other near-Earth asteroids [ http://neo.planetary.org/ABCsOfNEOs/index.html ] originally orbited in the main asteroid belt [ http://seds.lpl.arizona.edu/nineplanets/nineplanets/ asteroids.html ], between Jupiter [ http://galileo.jpl.nasa.gov/jupiter/jupiter.html ] and Mars [ http://nssdc.gsfc.nasa.gov/planetary/factsheet/ marsfact.html ]. Over time, the gravitational influence of Jupiter and other planets perturbed their orbits sending them on trajectories closer [ http://antwrp.gsfc.nasa.gov/apod/ap000226.html ] to Earth. |
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A 2000 Leonid Through Orion
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A 2000 Leonid Through Orion |
| Explanation |
The Leonid Meteor Shower this year could be described as good but not great. During November 17 and 18 the Earth crossed through several streams of sand-sized grit [ http://antwrp.gsfc.nasa.gov/apod/ap981121.html ] left orbiting the Sun by Comet Tempel-Tuttle [ http://antwrp.gsfc.nasa.gov/apod/ap991113.html ]. Several distinct peaks in meteor activity were reported [ http://www.imo.net/leo99/leo99index.html ], with rates approaching 400 meteors per hour for brief periods for some dark locations. Pictured above, a Leonid meteor [ http://leonids.hq.nasa.gov/leonids/ ] was caught from Florida [ http://www.state.fl.us ] streaking through the constellation of Orion [ http://antwrp.gsfc.nasa.gov/apod/ap000611.html ] on the morning of 2000 November 18. Visible as a red-tinged smudge to the left of the three nearly linear stars that compose Orion's belt [ http://www.itss.raytheon.com/cafe/qadir/q1981.html ] is the picturesque star-forming region known as the Orion Nebula [ http://antwrp.gsfc.nasa.gov/apod/ap001122.html ]. Next year, the Leonids Meteor Shower is expected [ http://www.arm.ac.uk/leonid/info2000.html ] by many to be much more active. |
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Venus' Evening Loop
| Title |
Venus' Evening Loop |
| Explanation |
From September 2000 through March 2001, astronomer Tunc Tezel patiently photographed the planet Venus on 25 different dates as it wandered [ http://zebu.uoregon.edu/~js/ast221/lectures/ lec06.html ] through the evening twilight. The pictures were taken from the same spot on the campus of the Middle East Technical University near Ankara, Turkey, and timed so that for each photo the Sun was [ http://aa.usno.navy.mil/data/docs/RS_OneYear.html ] 7 degrees below the horizon. Carefully registering and combining the pictures, he produced this composite image -- a stunning demonstration of Venus' grand [ http://stoner.eps.mcgill.ca/~bud/craters/ FaceOfVenus.html ] looping sky motion [ http://sunra.colorado.edu/david/ch1.html ] during its recent stint as planet Earth's evening star [ http://www.library.utoronto.ca/utel/rp/poems/ longfe10.html ]. As indicated, the first picture, taken September 28, 2000, finds Venus [ http://www.windows.ucar.edu/cgi-bin/tour_def/venus/ morning_star.html ] close to the western horizon [ http://antwrp.gsfc.nasa.gov/apod/ap990619.html ] and drifting south (left) with the passing days. By December however, Venus [ http://nssdc.gsfc.nasa.gov/planetary/planets/ venuspage.html ] was climbing well above the horizon after sunset and in January 2001 it reached its maximum apparent distance (elongation [ http://astrosun.tn.cornell.edu/courses/astro201/ planet_view.htm ]) from the Sun. March found Venus [ http://antwrp.gsfc.nasa.gov/apod/ap010308.html ] falling from the evening sky while moving rapidly north, finally appearing (far right) as a faint dot against the sunset glow on March 24. This month, Venus rises before dawn as the brilliant morning star [ http://stardate.utexas.edu/resources/ faqs/049.html ]. |
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Asteroid Eros Reconstructed
| Title |
Asteroid Eros Reconstructed |
| Explanation |
Orbiting the Sun [ http://www.nineplanets.org/sol.html ] between Mars [ http://pds.jpl.nasa.gov/planets/welcome/mars.htm ] and Earth [ http://nssdc.gsfc.nasa.gov/photo_gallery/photogallery-earth.html ], asteroid 433 Eros was visited by the robot spacecraft NEAR-Shoemaker [ http://near.jhuapl.edu/intro/faq.html ] in 2000 February. High-resolution surface measurements made by NEAR [ http://near.jhuapl.edu/NEAR/ ]'s Laser Rangefinder (NLR [ http://near.jhuapl.edu/instruments/NLR/index.html ]) have been combined into the above visualization [ http://svs.gsfc.nasa.gov/imagewall/eros.html ] based on the derived 3D model [ http://svs.gsfc.nasa.gov/imagewall/ eros.html#eros ] of the tumbling space rock [ http://antwrp.gsfc.nasa.gov/apod/ap000210.html ]. NEAR allowed scientists to discover that Eros [ http://www.gsfc.nasa.gov/GSFC/SpaceSci/Near/eros.htm ] is a single solid body, that its composition is nearly uniform, and that it formed during the early years of our Solar System [ http://www.nineplanets.org/overview.html ]. Mysteries remain, however, including why some rocks on the surface have disintegrated. On 2001 February 12, the NEAR mission drew to a dramatic close as it was crash landed [ http://antwrp.gsfc.nasa.gov/apod/ap010212.html ] onto the asteroid's surface [ http://antwrp.gsfc.nasa.gov/apod/ap000803.html ], surviving well enough [ http://antwrp.gsfc.nasa.gov/apod/ap010213.html ] to return an analysis of the composition [ http://antwrp.gsfc.nasa.gov/apod/ap010305.html ] of the surface regolith [ http://antwrp.gsfc.nasa.gov/apod/ap000829.html ]. Unless re-awakened by NASA [ http://www.nasa.gov/ ], NEAR will likely remain on the asteroid [ http://antwrp.gsfc.nasa.gov/apod/ap000327.html ] for billions of years as a monument to human ingenuity at the turn of the third millennium [ http://antwrp.gsfc.nasa.gov/apod/ap010101.html ]. |
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A Sun Pillar in Red and Viol
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| Title |
A Sun Pillar in Red and Violet |
| Explanation |
Sometimes the unknown is beautiful. In 2000 February near Lake Tahoe, Nevada [ http://silver.state.nv.us/ ], two amateur photographers noticed an unusual red column of light [ http://www.meteoros.de/englisch/ee08e.htm ] rise mysteriously from a setting sun [ http://antwrp.gsfc.nasa.gov/apod/ap980526.html ]. During the next few minutes, they were able to capture the pillar [ http://www.sundog.clara.co.uk/halo/pillar.htm ] and a photogenic sunset [ http://www.photolib.noaa.gov/historic/nws/nwind4.htm ] on film. Pictured above, the red column [ http://www.astrophys-assist.com/wilobs/weathwin/sunpillr.htm ] is seen above a serene Lake Tahoe [ http://tahoe.usgs.gov/ ] and snow-capped mountains across from Lake Tahoe-Nevada State Park [ http://www.state.nv.us/stparks/lt.htm ]. The mysterious column, they learned later, is a Sun Pillar [ http://antwrp.gsfc.nasa.gov/apod/ap010313.html ], a phenomenon where sunlight reflects off of distant falling ice crystals [ http://www.sundog.clara.co.uk/halo/crystals.htm ]. |
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Mercury on the Horizon
| Title |
Mercury on the Horizon |
| Explanation |
Have you ever seen the planet Mercury? Because Mercury [ http://www.seds.org/nineplanets/nineplanets/ mercury.html ] orbits so close to the Sun, it never wanders far from the Sun in Earth's sky [ http://antwrp.gsfc.nasa.gov/apod/ap020509.html ]. If trailing the Sun, Mercury [ http://antwrp.gsfc.nasa.gov/apod/mercury.html ] will be visible low on the horizon for only a short while after sunset [ http://antwrp.gsfc.nasa.gov/apod/ap020510.html ]. If leading the Sun, Mercury will be visible only shortly before sunrise. So at certain times of the year an informed skygazer [ http://skyandtelescope.com/observing/ataglance/ article_110_1.asp ] with a little determination can usually pick Mercury out from a site with an unobscured horizon. Above, a lot of determination has been combined with a little digital trickery [ http://www.astropix.com/HTML/J_DIGIT/ ETHICS.HTM ] to show Mercury's successive positions during March of 2000. Each picture was taken from the same location in Spain when the Sun itself was 10 degrees below the horizon [ http://antwrp.gsfc.nasa.gov/apod/ap970909.html ] and superposed on the single most photogenic sunset [ http://antwrp.gsfc.nasa.gov/apod/ap980526.html ]. Mercury is currently visible in the western sky [ http://starfieldobservatory.com/coming.htm ] after sunset, but will disappear in the Sun's glare after a few days. |
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Jupiter and Saturn Pas de De
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| Title |
Jupiter and Saturn Pas de Deux |
| Explanation |
Viewed from [ http://space.jpl.nasa.gov/ ] Earth, the solar system's [ http://solarsystem.nasa.gov/features/planets/ planetsfeat.html ] planets do a cosmic dance that is hard to appreciate on any single night. But consider this well planned animated sequence combining 23 pictures taken at approximately 2 week intervals from June 2000 through May 2001. It reveals the graceful looping or retrograde motion [ http://alpha.lasalle.edu/~smithsc/Astronomy/ retrograd.html ] of bright wanderers [ http://spacekids.hq.nasa.gov/osskids/animate/ mac.html ] Jupiter (leftmost) and Saturn. Loitering among the background stars are the familiar Pleiades (above right) and V-shaped Hyades (below left) star clusters [ http://hou.lbl.gov/~vhoette/Explorations/ StarHop/hyades_pleiades.html ]. The planets didn't actually loop [ http://antwrp.gsfc.nasa.gov/apod/ap010601.html ] by reversing the direction of their orbits, though. Their apparent retrograde motion [ http://www.scienceu.com/observatory/articles/ retro/retro.html ] is a reflection of the motion [ http://faculty.fullerton.edu/cmcconnell/Planets.html ] of the Earth itself. Retrograde motion [ http://csep10.phys.utk.edu/astr161/lect/retrograde/ retrograde.html ] can be seen each time Earth overtakes and laps [ http://www.physics.uci.edu/~wtruppel/ AstroPage.html ] planets orbiting farther from the Sun, Earth moving more rapidly through its own relatively close-in orbit. Astronomer Tunc Tezel captured Jupiter and Saturn's "paired" retrograde loop in this remarkable series made after the close alignment [ http://antwrp.gsfc.nasa.gov/apod/ap000505.html ] of these gas giants in May 2000. The next opportunity to see these two planets dance such a pas de deux will be in the year 2020. |
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The Eskimo Nebula from Hubbl
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| Title |
The Eskimo Nebula from Hubble |
| Explanation |
In 1787, astronomer William Herschel [ http://www.windows.ucar.edu/cgi-bin/tour_def/people/enlightenment/herschel.html] discovered the Eskimo Nebula [ http://www.seds.org/billa/twn/n2392x.html ]. From the ground, NGC 2392 resembles a person's head surrounded by a parka [ http://www.oregonlink.com/arctic/cormorant_parka.html ] hood. In 2000, the Hubble Space Telescope [ http://antwrp.gsfc.nasa.gov/apod/ap970306.html ] imaged the Eskimo Nebula. From space, the nebula displays gas clouds so complex they are not fully understood. The Eskimo Nebula [ http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1990ApJ...362..226O ] is clearly a planetary nebula [ http://antwrp.gsfc.nasa.gov/apod/planetary_nebulae.html ], and the gas seen above composed the outer layers of a Sun [ http://antwrp.gsfc.nasa.gov/apod/sun.html ]-like star only 10,000 years ago. The inner filaments visible above [ http://oposite.stsci.edu/pubinfo/pr/2000/07/pr-photos.html ] are being ejected by strong wind [ http://www-istp.gsfc.nasa.gov/Education/wsolwind.html ] of particles from the central star. The outer disk contains unusual light-year long orange filaments. The Eskimo Nebula lies about 5000 light-year [ http://www.treasure-troves.com/astro/Light-Year.html ]s away and is visible with a small telescope in the constellation [ http://www.emufarm.org/~cmbell/myth/myth.html ] of Gemini [ http://www.astro.wisc.edu/~dolan/constellations/constellations/Gemini.html ]. |
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Meteors and Northern Lights
| Title |
Meteors and Northern Lights |
| Explanation |
Skygazers report [ http://skyandtelescope.com/news/current/ article_696_1.asp ] that the annual Perseid meteor [ http://antwrp.gsfc.nasa.gov/apod/ap020811.html ] shower went pretty much as predicted, producing a meteor [ http://science.nasa.gov/spaceweather/meteors/ gallery_12aug02.html ] every few minutes during the dark early morning hours of August 12 and 13. And as the constellation Perseus [ http://www.astro.wisc.edu/~dolan/constellations/constellations/ Perseus.html ] rose above the horizon on the night of August 11, astrophotographer Wade Clark was anticipating recording images of the flashing meteor trails from the Mt. Baker Ski Area in northwest Washington, USA. But Clark was also treated to a colorful display of northern lights [ http://www.exploratorium.edu/learning_studio/ auroras/ ]. As a result, the stars of Perseus [ http://www.coldwater.k12.mi.us/lms/planetarium/myth/ perseus.html ] are arrayed near the center of his well composed skyscape along with trails of Perseid meteors [ http://comets.amsmeteors.org/meteors/showers/ perseids.html ] all viewed through the auroral glow [ http://www.windows.ucar.edu/spaceweather/ sun_earth8.html ]. The alluring scene might look familiar to watchers of bygone Perseids [ http://antwrp.gsfc.nasa.gov/apod/ap000821.html ]. For many, views of the meteor shower in 2000 [ http://spacescience.com/headlines/y2000/ ast14aug_1.htm ] also coincided with auroral displays, courtesy of the active Sun [ http://www.spaceweather.com/ ]. |
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The Seasons of Saturn
| Title |
The Seasons of Saturn |
| Explanation |
Since Saturn's [ http://www.nineplanets.org/saturn.html ] axis is tilted as it orbits the Sun [ http://www.nineplanets.org/sol.html ], Saturn has seasons [ http://www-spof.gsfc.nasa.gov/stargaze/ Sseason.htm ], like those of planet Earth ... but Saturn's seasons last for over seven years. So what season [ http://heritage.stsci.edu/2001/15/table.html#caption ] is it on Saturn now? Orbiting the equator, the tilt of the rings of Saturn [ http://ringmaster.arc.nasa.gov/saturn/saturn.html ] provides quite a graphic seasonal display. In fact, this month, Saturn's rings will reach their most "open" angle after appearing nearly edge [ http://antwrp.gsfc.nasa.gov/apod/ap950801.html ] on in the mid-1990s. The ringed planet [ http://antwrp.gsfc.nasa.gov/apod/ap020215.html ] is also well placed in evening skies [ http://stardate.org/nightsky/almanac/ ] providing a grand view as summer comes to Saturn's southern hemisphere and winter to the north. The Hubble Space Telescope took the above sequence of images [ http://heritage.stsci.edu/2001/15/ ] about a year apart, starting on the left in 1996 and ending on the right in 2000. Although they look solid, Saturn's Rings are likely less than 50 meters thick [ http://adsabs.harvard.edu/cgi-bin/ nph-bib_query?bibcode=1984Sci...223..396Z ] and consist of individually orbiting bits of ice and rock ranging in size from grains of sand to barn-sized boulders. |
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Mercury on the Horizon
| Title |
Mercury on the Horizon |
| Explanation |
Have you ever seen the planet Mercury? Because Mercury [ http://www.seds.org/nineplanets/nineplanets/ mercury.html ] orbits so close to the Sun, it never wanders far from the Sun in Earth's sky [ http://antwrp.gsfc.nasa.gov/apod/ap020509.html ]. If trailing the Sun, Mercury [ http://antwrp.gsfc.nasa.gov/apod/mercury.html ] will be visible low on the horizon for only a short while after sunset [ http://antwrp.gsfc.nasa.gov/apod/ap020510.html ]. If leading the Sun, Mercury will be visible only shortly before sunrise. So at certain times of the year an informed skygazer [ http://skyandtelescope.com/observing/ataglance/ article_110_1.asp ] with a little determination can usually pick Mercury out from a site with an unobscured horizon. Above, a lot of determination has been combined with a little digital trickery [ http://www.astropix.com/HTML/J_DIGIT/ ETHICS.HTM ] to show Mercury's successive positions during March of 2000. Each picture was taken from the same location in Spain when the Sun itself was 10 degrees below the horizon [ http://antwrp.gsfc.nasa.gov/apod/ap970909.html ] and superposed on the single most photogenic sunset [ http://antwrp.gsfc.nasa.gov/apod/ap980526.html ]. By the middle of this month, Mercury will again be well placed for viewing above the western horizon at sunset, but by the end of April it will have faded and dropped into the twilight. On May 7th, Mercury will cross [ http://sunearth.gsfc.nasa.gov/eclipse/OH/transit03.html ] the Sun's disk. |
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The Eskimo Nebula from Hubbl
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| Title |
The Eskimo Nebula from Hubble |
| Explanation |
In 1787, astronomer William Herschel [ http://www.windows.ucar.edu/cgi-bin/tour_def/people/enlightenment/herschel.html ] discovered the Eskimo Nebula [ http://www.seds.org/billa/twn/n2392x.html ]. From the ground, NGC 2392 resembles a person's head surrounded by a parka [ http://www.oregonlink.com/arctic/cormorant_parka.html ] hood. In 2000, the Hubble Space Telescope [ http://antwrp.gsfc.nasa.gov/apod/ap021124.html ] imaged the Eskimo Nebula [ http://www.noao.edu/outreach/aop/observers/n2392.html ]. From space, the nebula displays gas clouds so complex they are not fully understood. The Eskimo Nebula [ http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1990ApJ...362..226O ] is clearly a planetary nebula [ http://antwrp.gsfc.nasa.gov/apod/planetary_nebulae.html ], and the gas seen above composed the outer layers of a Sun [ http://antwrp.gsfc.nasa.gov/apod/sun.html ]-like star only 10,000 years ago. The inner filaments visible above [ http://hubblesite.org/newscenter/newsdesk/archive/releases/2000/07/image/a ] are being ejected by strong wind [ http://www-istp.gsfc.nasa.gov/Education/wsolwind.html ] of particles from the central star. The outer disk contains unusual light-year long orange filaments. |
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A Winter Solstice
| Title |
A Winter Solstice |
| Explanation |
Today is the Winter Solstice [ http://antwrp.gsfc.nasa.gov/apod/ap961221.html ], the shortest day of the year in the Northern Hemisphere [ http://antwrp.gsfc.nasa.gov/apod/ap961201.html ]. The yearly cycle of Seasons [ http://antwrp.gsfc.nasa.gov/apod/ap970923.html ] on planet Earth once again finds the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap971217.html ] at its lowest point in the Northern Sky. The Sun's own 11 year cycle of activity [ http://www.adler.uchicago.edu/asnc/solar/solar3.html ] is progressing toward a maximum which will occur in 2000-2001. This image of the Sun [ http://sohowww.nascom.nasa.gov/data/summary/ ] in the light [ http://seal.nascom.nasa.gov/explore/ ] of ionized Helium [ http://antwrp.gsfc.nasa.gov/apod/ap960520.html ] was recorded by the space-based SOHO observatory only three days ago and shows many prominences [ http://antwrp.gsfc.nasa.gov/apod/ap971120.html ] and active regions. |
|
Celebrating Hubble With NGC
…
| Title |
Celebrating Hubble With NGC 6751 |
| Explanation |
Planetary nebulae can [ http://antwrp.gsfc.nasa.gov/apod/ap040424.html ] look simple, round, and planet-like in small telescopes. But images from the orbiting Hubble Space Telescope [ http://hubblesite.org/reference_desk/faq/ category.php.cat=hst ] have become well known for showing these fluorescent gas shrouds [ http://antwrp.gsfc.nasa.gov/apod/ap050311.html ] of dying Sun-like stars to possess a staggering variety [ http://hubblesite.org/newscenter/newsdesk/archive/releases/ image_category/nebula/planetary/ ] of detailed symmetries and shapes [ http://antwrp.gsfc.nasa.gov/apod/ap040910.html ]. This composite color Hubble image of NGC 6751 [ http://hubblesite.org/newscenter/newsdesk/archive/releases/ 2000/12/ ] is a beautiful example of a classic planetary nebula with complex features. It was selected in April of 2000, to commemorate the tenth anniversary [ http://hubblesite.org/newscenter/newsdesk/future/ ] of Hubble in orbit. The colors were chosen to represent the relative temperature of the gas - blue, orange, and red indicating the hottest to coolest gas. Winds and radiation from the intensely hot central star [ http://antwrp.gsfc.nasa.gov/apod/ap050123.html ] (140,000 degrees [ http://www.unidata.ucar.edu/staff/ blynds/tmp.html ] Celsius [ http://www.astro.uu.se/history/Celsius_eng.html ]) have apparently created the nebula's streamer-like features. The nebula's [ http://heritage.stsci.edu/2000/12/fast_facts.html ] actual diameter is approximately 0.8 light-years or about 600 times the size of our solar system. NGC 6751 is 6,500 light-years distant in the high-flying constellation Aquila [ http://www.astro.wisc.edu/~dolan/constellations/ constellations/Aquila.html ]. |
|
Sunrise Over Kilimanjaro
| Title |
Sunrise Over Kilimanjaro |
| Explanation |
Is the Roof of Africa [ http://www.mos.org/kili/ ] on fire? A group hiking at 6 am near the top of Mt. Kilimanjaro [ http://volcano.und.nodak.edu/vwdocs/volc_images/img_kilimanjaro.html ] watched the rising sun peak above the clouds and the horizon light up red. Don't worry -- in this case the highest volcano in Africa [ http://www.cia.gov/cia/publications/factbook/reference_maps/africa.html ] is not even erupting. The spectacular sunrise [ http://antwrp.gsfc.nasa.gov/apod/ap031021.html ] colors are caused by light scattering off the atmosphere and small cloud particles. If all of the scattered light that makes the sky blue [ http://math.ucr.edu/home/baez/physics/General/BlueSky/blue_sky.html ] were added back into the scene, the sunrise would appear Sun-colored and not so red. A similar light scattering effect involving small airborne dust particles causes sunsets on Mars [ http://antwrp.gsfc.nasa.gov/apod/ap050620.html ] to be red and has been used to determine the sizes of particles in the rings of Saturn [ http://antwrp.gsfc.nasa.gov/apod/ap050525.html ]. During this trek in 2000 November, a group of about 30 reached the Kilomanjaro [ http://antwrp.gsfc.nasa.gov/apod/ap040911.html ] summit [ http://antwrp.gsfc.nasa.gov/apod/ap050306.html ] after a six-day climb. |
|
A Sun Pillar in Red and Viol
…
| Title |
A Sun Pillar in Red and Violet |
| Explanation |
Sometimes the unknown is beautiful. In 2000 February near Lake Tahoe, Nevada [ http://silver.state.nv.us/ ], two amateur photographers noticed an unusual red column of light [ http://antwrp.gsfc.nasa.gov/apod/ap020902.html ] rise mysteriously from a setting sun [ http://antwrp.gsfc.nasa.gov/apod/ap980526.html ]. During the next few minutes, they were able to capture the pillar [ http://www.sundog.clara.co.uk/halo/pillar.htm ] and a photogenic sunset [ http://www.photolib.noaa.gov/historic/nws/nwind4.htm ] on film. Pictured above, the red column [ http://www.astrophys-assist.com/wilobs/weathwin/sunpillr.htm ] is seen above a serene Lake Tahoe [ http://en.wikipedia.org/wiki/Lake_Tahoe ] and snow-capped mountains across from Lake Tahoe-Nevada State Park [ http://parks.nv.gov/lt.htm ]. The mysterious column, they learned later, is a Sun Pillar [ http://antwrp.gsfc.nasa.gov/apod/ap010313.html ], a phenomenon where sunlight reflects off of distant falling ice crystals [ http://www.sundog.clara.co.uk/halo/crystals.htm ]. |
|
Rotten Egg Nebula
| Title |
Rotten Egg Nebula |
| Description |
Violent gas collisions that produced supersonic shock fronts in a dying star are seen in a new, detailed image from NASA's Hubble Space Telescope. The picture, taken by Hubble's Wide Field and Planetary Camera 2, is online at http://www.jpl.nasa.gov/images/wfpc . The camera was designed and built by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Stars like our Sun will eventually die and expel most of their material outward into shells of gas and dust. These shells eventually form some of the most beautiful objects in the universe, called planetary nebulae."This new image gives us a rare view of the early death throes of stars like our Sun. For the first time, we can see phenomena leading to the formation of planetary nebulae. Until now, this had only been predicted by theory, but had never been seen directly," said Dr. Raghvendra Sahai, research scientist and member of the science team at JPL for the Wide Field and Planetary Camera 2. The object is sometimes called the Rotten Egg Nebula, because it contains a lot of sulphur, which would produce an awful odor if one could smell in space. The object is also known as the Calabash Nebula or by the technical name OH231.8+4.2. The densest parts of the nebula are composed of material ejected recently by the central star and accelerated in opposite directions. This material, shown as yellow in the image, is zooming away at speeds up to one and a half million kilometers per hour (one million miles per hour). Most of the star's original mass is now contained in these bipolar gas structures. A team of Spanish and American astronomers used NASA's Hubble Space Telescope to study how the gas stream rams into the surrounding material, shown in blue. They believe that such interactions dominate the formation process in planetary nebulae. Due to the high speed of the gas, shock-fronts are formed on impact and heat the surrounding gas. Although computer calculations have predicted the existence and structure of such shocks for some time, previous observations have not been able to prove the theory. This new Hubble image used filters that only let through light from ionized hydrogen and nitrogen atoms. Astronomers were able to distinguish the warmest parts of the gas heated by the violent shocks and found that they form a complex double-bubble shape. The bright yellow-orange colors in the picture show how dense, high-speed gas is flowing from the star, like supersonic speeding bullets ripping through a medium in opposite directions. The central star itself is hidden in the dusty band at the center. Much of the gas flow observed today seems to stem from a sudden acceleration that took place only about 800 years ago. The astronomers believe that 1,000 years from now, the Calabash Nebula will become a fully developed planetary nebula, like a butterfly emerging from its cocoon. The Calabash Nebula is 1.4 light years (more than 8 trillion miles) long and located some 5,000 light years (2,900 trillion, miles) from Earth in the constellation Puppis. The image was taken in December 2000 by the Wide Field and Planetary Camera 2. The image was originally released by the Hubble European Space Agency Information Centre, with a website at http://sci.esa.int/hubble. Additional information about the Hubble Space Telescope is online at http://www.stsci.edu . More information about the Wide Field and Planetary Camera 2 is at http://wfpc2.jpl.nasa.gov . Other scientists on the team include Valentin Bujarrabal and Javier Alcolea of Observatorio Astronomico Nacional, Spain, and Carmen Sanchez Contreras of JPL. The Space Telescope Science Institute, Baltimore, Md., manages space operations for Hubble for NASA's Office of Space Science, Washington, D.C. The institute is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract with the Goddard Space Flight Center, Greenbelt, Md. The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. JPL is a division of the California Institute of Technology in Pasadena. |
| Date |
12.02.1999 |
|
Doradus Nebula
| Title |
Doradus Nebula |
| Description |
A panoramic view of a vast, sculpted area of gas and dust where thousands of stars are being born has been captured by NASA's Hubble Space Telescope. The image, taken by Hubble's Wide Field and Planetary Camera 2, is online at http://oposite.stsci.edu/pubinfo/pr/2001/21 and http://www.jpl.nasa.gov/images/wfpc . The camera was designed and built by NASA's Jet Propulsion Laboratory, Pasadena, Calif. The photo offers an unprecedented, detailed view of the entire inner region of the fertile, star-forming 30 Doradus Nebula. The mosaic picture shows that ultraviolet radiation and high-speed material unleashed by the stars in the cluster, called R136 (the large blue blob left of center), are weaving a tapestry of creation and destruction, triggering the collapse of looming gas and dust clouds and forming pillar-like structures that incubate newborn stars. The 30 Doradus Nebula is in the Large Magellanic Cloud, a satellite galaxy of the Milky Way located 170,000 light-years from Earth. Nebulas like 30 Doradus are signposts of recent star birth. High-energy ultraviolet radiation from young, hot, massive stars in R136 causes surrounding gaseous material to glow. Previous Hubble telescope observations showed that R136 contains several dozen of the most massive stars known, each about 100 times the mass of the Sun and about 10 times as hot. These stellar behemoths formed about 2 million years ago. The stars in R136 produce intense "stellar winds," streams of material traveling at several million miles an hour. These winds push the gas away from the cluster and compress the inner regions of the surrounding gas and dust clouds (seen in the image as the pinkish material). The intense pressure triggers the collapse of parts of the clouds, producing a new star formation around the central cluster. Most stars in the nursery are not visible because they are still encased in cocoons of gas and dust. This mosaic image of 30 Doradus consists of five overlapping pictures taken between January 1994 and September 2000 by the Wide Field and Planetary Camera 2. Several color filters enhance important details in the stars and the nebula. Blue corresponds to the hot stars. The greenish color denotes hot gas energized by the central cluster of stars. Pink depicts the glowing edges of the gas and dust clouds facing the cluster, which are being bombarded by winds and radiation. Reddish-brown represents the cooler surfaces of the clouds, which are not receiving direct radiation from the central cluster. Additional information about the Hubble Space Telescope is at http://www.stsci.edu . More information about the Wide Field and Planetary Camera 2 is at http://wfpc2.jpl.nasa.gov . The Space Telescope Science Institute, Baltimore, Md., manages space operations for Hubble for NASA's Office of Space Science, Washington, D.C. The institute is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract with the Goddard Space Flight, Center, Greenbelt, Md. The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. JPL is a division of the California Institute of Technology in Pasadena. |
| Date |
12.01.1999 |
|
Mars and Earth Dust Storms
| title |
Mars and Earth Dust Storms |
| Description |
seasonal meteorology [ http://www.thirdworld.org/role.html ] and the health of biological communities [ http://catbert.er.usgs.gov/african_dust/ ]. Photo Credit: NASA/JPL/Malin Space Science Systems, Spring on Mars...in either hemisphere...is a time for local and regional dust storms. These storms arise as the seasonal carbon dioxide frost cap, which can extend almost half-way to the equator, sublimes in the warming spring environment. Several factors promote these dust storms: * the atmospheric pressure is increasing as carbon dioxide frost (CO2) sublimes--higher pressure allows more dust to be suspended, and for a longer time, * the temperature contrast between the frost covered surface and immediately adjacent, recently defrosted surfaces is quite high, creating thermally-generated winds that circulate onto and off of the frost cap edge, * similar, temperature-driven winds arise as sublimation of frost covering sun-facing slopes and dark sandy surfaces deep within the polar region creates intense slope winds away from the higher-standing layered deposits and permanent cap. The roughly circular, polar orbit of the Mars Global Surveyor (MGS) spacecraft affords a view not unlike that seen by low Earth-orbiting environmental satellites. Mars is roughly 6800 km (4226 mi) in diameter, and a 370 km (230 mi) average altitude gives a diameter to altitude ratio for MGS of 18.4:1. For comparison, the SeaStar spacecraft in Earth orbit follows a very similar orbit: it's the diameter to altitude ratio is 17.5:1 (12,760 km or 7,928 mi diameter relative to a 705 km or 438 mi altitude). Each spacecraft covers the entire planet in 12 orbits. In this figure, we compare a recent dust storm on Mars with one that occurred earlier this year on Earth. The top image shows a martian north polar dust storm observed on 29 August 2000. This image is part of the Mars Orbiter Camera (MOC) daily global map--a low resolution, two-color view of Mars acquired from pole to pole every orbit. The storm is moving as a front, outward from a central "jet," and marginal "vortices" can be seen. In this image it extends about 900 km (560 mi) out from the north polar seasonal frost cap. The region on the right side of the Mars picture includes the north pole. The bottom image shows a terrestrial dust storm, seen in a SeaWiFS image [ http://seawifs.gsfc.nasa.gov/SEAWIFS/IMAGES/SEAWIFS_GALLERY.html ], acquired on 26 February 2000. This storm extends about 1800 km (1100 mi) off the coast of northwest Africa near the Earth's equator. Both images are shown at the same scale, 4 km (2.5 mi) per pixel. Dust storms play an important role in governing the climate of Mars. The rare, global storms alter the planet's total heat balance and promote variations in seasonal frost formation and dissipation, and greatly affect the distribution of water vapor. Local and regional storms, especially those in the polar regions, affect the rate at which seasonal frost evolves, and control local and regional weather patterns. On Earth, dust storms are also being recognized as contributing to environmental change, potentially influencing |
|
First Monthly CERES Global L
…
nasa, nasaimageofthedaygalle
…
*NASA Releases Terra's First
…
ceres_monthly_200003
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2000-03-01 |
| creator |
NASA -- Data courtesy CERES instrument team |
| identifier |
ceres_monthly_200003 |
|
ASTER Andes
PIA02654
Sol (our sun)
ASTER
| Title |
ASTER Andes |
| Original Caption Released with Image |
In this image of the Andes along the Chile-Bolivia border, the visible and infrared data have been computer enhanced to exaggerate the color differences of the different materials. The scene is dominated by the Pampa Luxsar lava complex, occupying the upper right two-thirds of the scene. Lava flows are distributed around remnants of large dissected cones, the largest of which is Cerro Luxsar. On the middle left edge of the image are the Olca and Parumastrato volcanoes, which appear in blue due to a lack of vegetation (colored red in this composite). This image covers an area 60 kilometers (37 miles) wide and 60 kilometers (37 miles) long in three bands of the reflected visible and infrared wavelength region. It was acquired on April 7, 2000. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. science team leader, Moshe Pniel of JPL is the project manager. ASTER is the only high-resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface. The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping and monitoring dynamic conditions and temporal change. Examples of applications include monitoring glacial advances and retreats, potentially active volcanoes, thermal pollution, and coral reef degradation, identifying crop stress, determining cloud morphology and physical properties, evaluating wetlands, mapping surface temperature of soils and geology, and measuring surface heat balance. |
|
ASTER Images San Francisco B
…
PIA02606
Sol (our sun)
ASTER
| Title |
ASTER Images San Francisco Bay Area |
| Original Caption Released with Image |
This image of the San Francisco Bay region was acquired on March 3, 2000 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters about 50 to 300 feet ), ASTER will image Earth for the next 6 years to map and monitor the changing surface of our planet. Image: This image covers an area 60 kilometers (37 miles) wide and 75 kilometers (47 miles) long in three bands of the reflected visible and infrared wavelength region. The combination of bands portrays vegetation in red, and urban areas in gray. Sediment in the Suisun Bay, San Pablo Bay, San Francisco Bay, and the Pacific Ocean shows up as lighter shades of blue. Along the west coast of the San Francisco Peninsula, strong surf can be seen as a white fringe along the shoreline. A powerful rip tide is visible extending westward from Daly City into the Pacific Ocean. In the lower right corner, the wetlands of the South San Francisco Bay National Wildlife Refuge appear as large dark blue and brown polygons. The high spatial resolution of ASTER allows fine detail to be observed in the scene. The main bridges of the area (San Mateo, San Francisco-Oakland Bay, Golden Gate, Richmond-San Rafael, Benicia-Martinez, and Carquinez) are easily picked out, connecting the different communities in the Bay area. Shadows of the towers along the Bay Bridge can be seen over the adjacent bay water. With enlargement the entire road network can be easily mapped, individual buildings are visible, including the shadows of the high-rises in downtown San Francisco. Inset: This enlargement of the San Francisco Airport highlights the high spatial resolution of ASTER. With further enlargement and careful examination, airplanes can be seen at the terminals. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. Science team leader, Moshe Pniel of JPL is the project manager. ASTER is the only high resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface. The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring dynamic conditions and temporal change. Example, applications are: monitoring glacial advances and retreats, monitoring potentially active volcanoes, identifying crop stress, determining cloud morphology and physical properties, wetlands evaluation, thermal pollution monitoring, coral reef degradation, surface temperature mapping of soils and geology, and measuring surface heat balance. |
|
ASTER Images Tokyo
PIA02607
Sol (our sun)
ASTER
| Title |
ASTER Images Tokyo |
| Original Caption Released with Image |
This image of the city of Tokyo was acquired on March 22, 2000 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image the Earth for the next 6 years to map and monitor the changing surface of our planet. This false color infrared image covers an area 60 km wide and 75 km long in three bands of the short wavelength infrared region, with a spatial resolution of 15 m. It shows part of the Tokyo metropolitan area extending south to Yokohama, included are the Ginza District, Haneda airport and the Imperial Palace. To the west, Tokyo is hemmed in by mountains, covered with forests (displayed in red), on the southeast, Tokyo Bay is one of the world's great harbors. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. Science team leader, Moshe Pniel of JPL is the project manager. ASTER is the only high resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface. The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats, monitoring potentially active volcanoes, identifying crop stress, determining cloud morphology and physical properties, wetlands evaluation, thermal pollution monitoring, coral reef degradation, surface temperature mapping of soils and geology, and measuring surface heat balance. |
|
ASTER Images San Francisco B
…
PIA02605
Sol (our sun)
ASTER
| Title |
ASTER Images San Francisco Bay Area |
| Original Caption Released with Image |
These images of the San Francisco Bay region were acquired on March 3, 2000 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. Each covers an area 60 kilometers (37 miles) wide and 75 kilometers (47 miles) long. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image the Earth for the next 6 years to map and monitor the changing surface of our planet. Upper Left: The color infrared composite uses bands in the visible and reflected infrared. Vegetation is red, urban areas are gray, sediment in the bays shows up as lighter shades of blue. Thanks to the 15 meter (50-foot) spatial resolution, shadows of the towers along the Bay Bridge can be seen. Upper right: A composite of bands in the short wave infrared displays differences in soils and rocks in the mountainous areas. Even though these regions appear entirely vegetated in the visible, enough surface shows through openings in the vegetation to allow the ground to be imaged. Lower left: This composite of multispectral thermal bands shows differences in urban materials in varying colors. Separation of materials is due to differences in thermal emission properties, analogous to colors in the visible. Lower right: This is a color coded temperature image of water temperature, derived from the thermal bands. Warm waters are in white and yellow, colder waters are blue. Suisun Bay in the upper right is fed directly from the cold Sacramento River. As the water flows through San Pablo and San Francisco Bays on the way to the Pacific, the waters warm up. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. Science team leader, Moshe Pniel of JPL is the project manager. ASTER is the only high resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface. The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats, monitoring potentially active volcanoes, identifying crop stress, determining cloud morphology and physical properties, wetlands, evaluation, thermal pollution monitoring, coral reef degradation, surface temperature mapping of soils and geology, and measuring surface heat balance. |
|
ASTER Suez Canal
PIA02661
Sol (our sun)
ASTER
| Title |
ASTER Suez Canal |
| Original Caption Released with Image |
One of the most important waterways in the world, the Suez Canal runs north to south across the Isthmus of Suez in northeastern Egypt. This image of the canal covers an area 36 kilometers (22 miles) wide and 60 kilometers (47 miles) long in three bands of the reflected visible and infrared wavelength region. It shows the northern part of the canal, with the Mediterranean Sea just visible in the upper right corner. The Suez Canal connects the Mediterranean Sea with the Gulf of Suez, an arm of the Red Sea. The artificial canal provides an important shortcut for ships operating between both European and American ports and ports located in southern Asia, eastern Africa, and Oceania. With a length of about 195 kilometers (121 miles) and a minimum channel width of 60 meters (197 feet), the Suez Canal is able to accommodate ships as large as 150,000 tons fully loaded. Because no locks interrupt traffic on this sea level waterway, the transit time only averages about 15 hours. ASTER acquired this scene on May 19, 2000. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. science team leader, Moshe Pniel of JPL is the project manager. ASTER is the only high-resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. science team leader, Moshe Pniel of JPL is the project manager. ASTER is the only high-resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface. The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping and monitoring dynamic conditions and temporal, change. Examples of applications include monitoring glacial advances and retreats, potentially active volcanoes, thermal pollution, and coral reef degradation, identifying crop stress, determining cloud morphology and physical properties, evaluating wetlands, mapping surface temperature of soils and geology, and measuring surface heat balance. |
|
ASTER Washington, D.C.
PIA02655
Sol (our sun)
ASTER
| Title |
ASTER Washington, D.C. |
| Original Caption Released with Image |
The White House, the Jefferson Memorial, and the Washington Monument with its shadow are all visible in this image of Washington, D.C. With its 15-meter spatial resolution, ASTER can see individual buildings. Taken on June 1, 2000, this image covers an area 14 kilometers (8.5 miles) wide and 13.7 kilometers (8.2 miles) long in three bands of the reflected visible and infrared wavelength region. The combination of visible and near infrared bands displays vegetation in red and water in dark grays. The Potomac River flows from the middle left to the bottom center. The large red area west of the river is Arlington National Cemetery. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. science team leader, Moshe Pniel of JPL is the project manager. ASTER is the only high-resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface. The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping and monitoring dynamic conditions and temporal change. Examples of applications include monitoring glacial advances and retreats, potentially active volcanoes, thermal pollution, and coral reef degradation, identifying crop stress, determining cloud morphology and physical properties, evaluating wetlands, mapping surface temperature of soils and geology, and measuring surface heat balance. |
|
ASTER Waves
PIA02662
Sol (our sun)
ASTER
| Title |
ASTER Waves |
| Original Caption Released with Image |
The pattern on the right half of this image of the Bay of Bengal is the result of two opposing wave trains colliding. This ASTER sub-scene, acquired on March 29, 2000, covers an area 18 kilometers (13 miles) wide and 15 kilometers (9 miles) long in three bands of the reflected visible and infrared wavelength region. The visible and near-infrared bands highlight surface waves due to specular reflection of sunlight off of the wave faces. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. science team leader, Moshe Pniel of JPL is the project manager. ASTER is the only high-resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. science team leader, Moshe Pniel of JPL is the project manager. ASTER is the only high-resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface. The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping and monitoring dynamic conditions and temporal change. Examples of applications include monitoring glacial advances and retreats, potentially active volcanoes, thermal pollution, and coral reef degradation, identifying crop stress, determining cloud morphology and physical properties, evaluating wetlands, mapping surface temperature of soils and geology, and measuring surface heat balance. |
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ASTER Paris
PIA02660
Sol (our sun)
ASTER
| Title |
ASTER Paris |
| Original Caption Released with Image |
The Eiffel Tower and its shadow can be seen next to the Seine in the left middle of this ASTER image of Paris. Based on the length of the shadow and the solar elevation angle of 59 degrees, we can calculate its height as 324 meters (1,054 feet), compared to its actual height of 303 meters (985 feet). Acquired on July 23, 2000, this image covers an area 23 kilometers (15 miles) wide and 20 kilometers (13 miles) long in three bands of the reflected visible and infrared wavelength region. Known as the City of Light, Paris has been extolled for centuries as one of the great cities of the world. Its location on the Seine River, at a strategic crossroads of land and river routes, has been the key to its expansion since the Parisii tribe first settled here in the 3rd century B.C. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. science team leader, Moshe Pniel of JPL is the project manager. ASTER is the only high-resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. science team leader, Moshe Pniel of JPL is the project manager. ASTER is the only high-resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface. The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping and monitoring dynamic conditions and temporal change. Examples of applications include monitoring glacial advances and retreats, potentially active volcanoes, thermal pollution, and coral reef degradation, identifying crop stress, determining cloud morphology and physical properties;, evaluating wetlands, mapping surface temperature of soils and geology, and measuring surface heat balance. |
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ASTER-SRTM Perspective of Mo
…
PIA02771
Sol (our sun)
ASTER, C-Band Interferometri
…
| Title |
ASTER-SRTM Perspective of Mount Oyama Volcano, Miyake-Jima Island, Japan |
| Original Caption Released with Image |
Mount Oyama is a 820-meter-high (2,700 feet) volcano on the island of Miyake-Jima, Japan. In late June 2000, a series of earthquakes alerted scientists to possible volcanic activity. On June 27, authorities evacuated 2,600 people, and on July 8 the volcano began erupting and erupted five times over that week. The dark gray blanket covering green vegetation in the image is the ash deposited by prevailing northeasterly winds between July 8 and 17. This island is about 180 kilometers (110 miles) south of Tokyo and is part of the Izu chain of volcanic islands that runs south from the main Japanese island of Honshu. Miyake-Jima is home to 3,800 people. The previous major eruptions of Mount Oyama occurred in 1983 and 1962, when lava flows destroyed hundreds of houses. An earlier eruption in 1940 killed 11 people. This image is a perspective view created by combining image data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) aboard NASA's Terra satellite with an elevation model from the Shuttle Radar Topography Mission (SRTM). Vertical relief is exaggerated, and the image includes cosmetic adjustments to clouds and image color to enhance clarity of terrain features. The ASTER instrument is a cooperative project between NASA, JPL, and the Japanese Ministry of International Trade and Industry. Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11,2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense(DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise,Washington, DC. Size: Island is approximately 8 kilometers (5 miles) in diameter Location: 34.1 deg. North lat., 139.5 deg. East lon. Orientation: View toward the west-southwest. Image Data: ASTER visible and near infrared Date Acquired: February 20, 2000 (SRTM), July 17, 2000 (ASTER) Image: NASA/JPL/NIMA/MITI |
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ASTER Gibraltar
PIA02657
Sol (our sun)
ASTER
| Title |
ASTER Gibraltar |
| Original Caption Released with Image |
The Strait of Gibraltar separates Spain from Morocco. This image, acquired on July 5, 2000, covers an area 34 kilometers (21 miles) wide and 59 kilometers (37 miles) long in three bands of the reflected visible and infrared wavelength region. The promontory on the eastern side of the conspicuous Spanish port is the Rock of Gibraltar. Once one of the two classical Pillars of Hercules, the Rock was crowned with silver columns by Phoenician mariners to mark the limits of safe navigation for the ancient Mediterranean peoples. The rocky promontory still commands the western entrance to the Mediterranean Sea. The rocky limestone and shale ridge rises abruptly from the sea, to a maximum elevation of 426 meters (1,398 feet). A British colony, Gibraltar occupies a narrow strip of land at the southernmost tip of the Iberian Peninsula. It is separated from the Spanish mainland by a neutral zone contained on a narrow, sandy isthmus. Because of its strategic location and formidable topography, Gibraltar serves mainly as a British fortress. Most of its sparse land is taken up by air and naval installations, and the civilian population is small. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. science team leader, Moshe Pniel of JPL is the project manager. ASTER is the only high-resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. science team leader, Moshe Pniel of JPL is the project manager. ASTER is the only high-resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface. The broad spectral coverage and high spectral resolution of ASTER will provide scientists, in numerous disciplines with critical information for surface mapping and monitoring dynamic conditions and temporal change. Examples of applications include monitoring glacial advances and retreats, potentially active volcanoes, thermal pollution, and coral reef degradation, identifying crop stress, determining cloud morphology and physical properties, evaluating wetlands, mapping surface temperature of soils and geology, and measuring surface heat balance. |
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ASTER Mexicali
PIA02659
Sol (our sun)
ASTER
| Title |
ASTER Mexicali |
| Original Caption Released with Image |
Dramatic differences in land use patterns are highlighted in this image of the U.S.-Mexico border. Lush, regularly gridded agricultural fields on the U.S. side contrast with the more barren fields of Mexico This June 12, 2000, sub-scene combines visible and near infrared bands, displaying vegetation in red. The town of Mexicali-Calexico spans the border in the middle of the image, El Centro, California, is in the upper left. Watered by canals fed from the Colorado River, California's Imperial Valley is one of the country's major fruit and vegetable producers. This image covers an area 24 kilometers (15 miles) wide and 30 kilometers (19 miles) long in three bands of the reflected visible and infrared wavelength region. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. science team leader, Moshe Pniel of JPL is the project manager. ASTER is the only high-resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. science team leader, Moshe Pniel of JPL is the project manager. ASTER is the only high-resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface. The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping and monitoring dynamic conditions and temporal change. Examples of applications include monitoring glacial advances and retreats, potentially active volcanoes, thermal pollution, and coral reef degradation, identifying crop stress, determining cloud morphology and physical properties, evaluating wetlands, mapping surface temperature of soils and, geology, and measuring surface heat balance. |
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ASTER Images the Island of H
…
PIA02604
Sol (our sun)
ASTER
| Title |
ASTER Images the Island of Hawaii |
| Original Caption Released with Image |
These images of the Island of Hawaii were acquired on March 19, 2000 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image Earth for the next 6 years to map and monitor the changing surface of our planet. Data are shown from the short wavelength and thermal infrared spectral regions, illustrating how different and complementary information is contained in different parts of the spectrum. Left image: This false-color image covers an area 60 kilometers (37 miles) wide and 120 kilometers (75 miles) long in three bands of the short wavelength infrared region. While, much of the island was covered in clouds, the dominant central Mauna Loa volcano, rising to an altitude of 4115 meters (13,500 feet), is cloud-free. Lava flows can be seen radiating from the central crater in green and black tones. As they reach lower elevations, the flows become covered with vegetation, and their image color changes to yellow and orange. Mauna Kea volcano to the north of Mauna Loa has a thin cloud-cover, producing a bluish tone on the image. The ocean in the lower right appears brown due to the color processing. Right image: This image is a false-color composite of three thermal infrared bands. The brightness of the colors is proportional to the temperature, and the hues display differences in rock composition. Clouds are black, because they are the coldest objects in the scene. The ocean and thick vegetation appear dark green because they are colder than bare rock surfaces, and have no thermal spectral features. Lava flows are shades of magenta, green, pink and yellow, reflecting chemical changes due to weathering and relative age differences. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. Science team leader, Moshe Pniel of JPL is the project manager. ASTER is the only high resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface. The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring dynamic conditions and temporal change. Example applications, are: monitoring glacial advances and retreats, monitoring potentially active volcanoes, identifying crop stress, determining cloud morphology and physical properties, wetlands evaluation, thermal pollution monitoring, coral reef degradation, surface temperature mapping of soils and geology, and measuring surface heat balance. |
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ASTER Dunes
PIA02656
Sol (our sun)
ASTER
| Title |
ASTER Dunes |
| Original Caption Released with Image |
This image of Saudi Arabia shows a great sea of linear dunes in part of the Rub' al Khali, or the Empty Quarter. Acquired on June 25, 2000, the image covers an area 37 kilometers (23 miles) wide and 28 kilometers (17 miles) long in three bands of the reflected visible and infrared wavelength region. The dunes are yellow due to the presence of iron oxide minerals. The inter-dune area is made up of clays and silt and appears blue due to its high reflectance in band 1. The Rub' al Khali is the world's largest continuous sand desert. It covers about 650,000 square kilometers (250,966 square miles) and lies mainly in southern Saudi Arabia, though it does extend into the United Arab Emirates, Oman, and Yemen. One of the world's driest areas, it is uninhabited except for the Bedouin nomads who cross it. The first European to travel through the desert was Bertram Thomas in 1930. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. science team leader, Moshe Pniel of JPL is the project manager. ASTER is the only high-resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface. The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping and monitoring dynamic conditions and temporal change. Examples of applications include monitoring glacial advances and retreats, potentially active volcanoes, thermal pollution, and coral reef degradation, identifying crop stress, determining cloud morphology and physical properties, evaluating wetlands, mapping surface temperature of soils and geology, and measuring surface heat balance. |
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ASTER View of Sharm El Sheik
…
PIA02667
Sol (our sun)
ASTER
| Title |
ASTER View of Sharm El Sheik, Egypt |
| Original Caption Released with Image |
The Red Sea golf resort in Sharm El Sheik, Egypt, where President Clinton met with Israeli Prime Minister Ehud Barak and Palestinian Authority President Yasser Arafat, stands out against the desert landscape in this image acquired on August 25, 2000. This image of the southern tip of the Sinai Peninsula shows an area about 30 by 40 kilometers (19 by 25 miles) in the visible and near infrared wavelength region. Vegetation appears in red. The blue areas in the water at the top and bottom of the image are coral reefs. The airport is visible just to the north of the golf resort. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, Calif., is the U.S. Science team leader, Moshe Pniel of JPL is the project manager. ASTER is the only high resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface. The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats, monitoring potentially active volcanoes, identifying crop stress, determining cloud morphology and physical properties, wetlands Evaluation, thermal pollution monitoring, coral reef degradation, surface temperature mapping of soils and geology, and measuring surface heat balance. |
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ASTER Tibet
PIA02658
Sol (our sun)
ASTER
| Title |
ASTER Tibet |
| Original Caption Released with Image |
The Kunlun fault is one of the gigantic strike-slip faults that bound the north side of Tibet. Left-lateral motion along the 1,500-kilometer (932-mile) length of the Kunlun has occurred uniformly for the last 40,000 years at a rate of 1.1 centimeter per year, creating a cumulative offset of more than 400 meters (1300 feet). In this image, two splays of the fault are clearly seen crossing from east to west. The northern fault juxtaposes sedimentary rocks of the mountains against alluvial fans. Its trace is also marked by lines of vegetation, which appear red in the image. The southern, younger fault cuts through the alluvium. A dark linear area in the center of the image is wet ground where groundwater has pounded against the fault. Measurements from the image of displacements of young streams that cross the fault show 15 to 75 meters (16 to 82 yards) of left-lateral offset. This image of Tibet covers an area 40 kilometers (25 miles) wide and 15 kilometers (10 miles) long in three bands of the reflected visible and infrared wavelength region. ASTER acquired the scene on July 20, 2000. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. science team leader, Moshe Pniel of JPL is the project manager. ASTER is the only high-resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. science team leader, Moshe Pniel of JPL is the project manager. ASTER is the only high-resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface. The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical, information for surface mapping and monitoring dynamic conditions and temporal change. Examples of applications include monitoring glacial advances and retreats, potentially active volcanoes, thermal pollution, and coral reef degradation, identifying crop stress, determining cloud morphology and physical properties, evaluating wetlands, mapping surface temperature of soils and geology, and measuring surface heat balance. |
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Tsunami Inundation, North of
…
PIA06671
Sol (our sun)
ASTER, SIR-C/X-SAR
| Title |
Tsunami Inundation, North of Phuket, Thailand ASTER Images and SRTM Elevation Model |
| Original Caption Released with Image |
Figure 1 The Indian Ocean coastline north of Phuket, Thailand is a major tourist destination that was in the path of the tsunami produced by a giant offshore earthquake on December 26, 2004. This disaster resulted in a heavy loss of life. These simulated natural color ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) images show a 27 kilometer (17-mile) long stretch of coast 80 kilometers (50 miles) north of the Phuket airport in the Khao Lak area on December 31 (middle) and also two years earlier (left). The changes along the coast are obvious (changing from green to grey) where the vegetation was stripped away by the tsunami. The image on the right is a copy of the later ASTER scene but it includes highlighting in red for areas that have elevations within 10 meters (33 feet) of sea level. This elevation information was supplied by the Shuttle Radar Topography Mission (SRTM). The red areas appear to include most of the tsunami inundated areas. The geographic correspondence of the imaged damage and the highlighted elevation range is quite good in the middle and upper parts of the scene and is consistent with an early field report of about 10 meters of inundation. In the south, the elevation range corresponds to a much wider area than the actual damage, but this is to be expected for areas increasingly far from the coast. Offshore bathymetry (depth variations), coastal landforms, distance from the coast, and additional factors other than elevation range control the damage extent. But elevation measurements along the coast, as provided by SRTM, give a general indication of areas at risk, as now confirmed by ASTER. ASTER images Earth to map and monitor the changing surface of our planet with its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet). These data provide scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats, monitoring potentially active volcanoes, identifying crop stress, determining cloud morphology and physical properties, wetlands evaluation, thermal pollution monitoring, coral reef degradation, surface temperature mapping of soils and geology, and measuring surface heat balance. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate. Elevation data used in this image were acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour,, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Geospatial-Intelligence Agency (NGA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Science Mission Directorate, Washington, D.C. Size: 9.75 x 27.6 kilometers (6.0 x 17.1 miles), Location: 8.6 degrees North latitude, 98.3 degrees East longitude Orientation: Top is 8.25 degrees east of North Image Data: ASTER Bands 1, 2, 3 mixed for simulated true color. Date Acquired: November 15, 2002 and December 31, 2004 (ASTER), February 2000 (SRTM) |
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Tsunami Inundation, North of
…
PIA06671
Sol (our sun)
ASTER, SIR-C/X-SAR
| Title |
Tsunami Inundation, North of Phuket, Thailand ASTER Images and SRTM Elevation Model |
| Original Caption Released with Image |
Figure 1 The Indian Ocean coastline north of Phuket, Thailand is a major tourist destination that was in the path of the tsunami produced by a giant offshore earthquake on December 26, 2004. This disaster resulted in a heavy loss of life. These simulated natural color ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) images show a 27 kilometer (17-mile) long stretch of coast 80 kilometers (50 miles) north of the Phuket airport in the Khao Lak area on December 31 (middle) and also two years earlier (left). The changes along the coast are obvious (changing from green to grey) where the vegetation was stripped away by the tsunami. The image on the right is a copy of the later ASTER scene but it includes highlighting in red for areas that have elevations within 10 meters (33 feet) of sea level. This elevation information was supplied by the Shuttle Radar Topography Mission (SRTM). The red areas appear to include most of the tsunami inundated areas. The geographic correspondence of the imaged damage and the highlighted elevation range is quite good in the middle and upper parts of the scene and is consistent with an early field report of about 10 meters of inundation. In the south, the elevation range corresponds to a much wider area than the actual damage, but this is to be expected for areas increasingly far from the coast. Offshore bathymetry (depth variations), coastal landforms, distance from the coast, and additional factors other than elevation range control the damage extent. But elevation measurements along the coast, as provided by SRTM, give a general indication of areas at risk, as now confirmed by ASTER. ASTER images Earth to map and monitor the changing surface of our planet with its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet). These data provide scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats, monitoring potentially active volcanoes, identifying crop stress, determining cloud morphology and physical properties, wetlands evaluation, thermal pollution monitoring, coral reef degradation, surface temperature mapping of soils and geology, and measuring surface heat balance. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate. Elevation data used in this image were acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour,, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Geospatial-Intelligence Agency (NGA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Science Mission Directorate, Washington, D.C. Size: 9.75 x 27.6 kilometers (6.0 x 17.1 miles), Location: 8.6 degrees North latitude, 98.3 degrees East longitude Orientation: Top is 8.25 degrees east of North Image Data: ASTER Bands 1, 2, 3 mixed for simulated true color. Date Acquired: November 15, 2002 and December 31, 2004 (ASTER), February 2000 (SRTM) |
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Stereo Pair with ASTER Image
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PIA03363
Sol (our sun)
C-Band Interferometric Radar
| Title |
Stereo Pair with ASTER Image, Iturralde Structure, Bolivia |
| Original Caption Released with Image |
An 8-kilometer (5-mile) wide crater of possible impact origin is shown in this stereoscopic view of an isolated part of the Bolivian Amazon. The view is derived from an Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite image and a Shuttle Radar Topography Mission (SRTM) elevation model. The circular feature covering much of the image, known as the Iturralde Structure, is possibly the Earth's most recent "big" impact event recording collision with a meteor or comet that might have occurred between 11,000 and 30,000 years ago. Although the structure was identified on satellite photographs in the mid-1980s, its location is so remote that it has only been visited by scientific investigators twice, most recently by a team from NASA's Goddard Space Flight Center in September 2002. Lying in an area of very low relief, the landform is a quasi-circular closed depression only about 20 meters (66 feet) in depth, with sharply defined sub-angular "rim" materials. It resembles a "cookie cutter" in that its appearance "cuts" the heavily vegetated soft-sediments and pampas of this part of Bolivia. The SRTM data have provided investigators with the first topographic map of the site and will allow studies of its three-dimensional structure crucial to determining whether it actually is of impact origin. This stereoscopic image was generated by first draping the ASTER satellite image over the Shuttle Radar Topography Mission digital elevation model. Two differing perspectives were then calculated, one for each eye. They can be seen in 3-D by viewing the left image with the right eye and the right image with the left eye (cross-eyed viewing) or by downloading and printing the image pair and viewing them with a stereoscope. When stereoscopically merged, the result is a vertically exaggerated view of Earth's surface in its full three dimensions. Thick vegetation in part defines the surface that the SRTM radar sees as it maps the terrain. Much of the local "topography" in this area is a measure of tree height (typically up to 13 meters, or 40 feet). This effect is easily seen here, where the ground surface relief is very low. Interpretative separation of the ground surface and vegetative features can typically be made by recognition of their characteristic patterns. However, by integrating the ASTER data into the visualization, spectral colors help the recognition of terrain features (green vegetation and blue water). The ASTER instrument is a cooperative project between NASA, JPL, and the Japanese Ministry of International Trade and Industry, and it flies aboard NASA's Terra satellite. Elevation data used in this image was acquired by the Shuttle Radar Topography Mission aboard Space Shuttle Endeavour, launched on Feb. 11, 2000. The mission used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Endeavour in 1994. The Shuttle Radar Topography, Mission was designed to collect 3-D measurements of Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Size: 16.3 kilometers (10.1 miles) North-South by 14.5 kilometers (9.0 miles) East-West Location: 12.6 degrees South latitude, 67.7 degrees West longitude Orientation: North at top, Latitude-Longitude projection Image: ASTER band 1,2,3 combinations as red, green, blue. Original Data Resolution: SRTM 1 arcsecond (about 30 meters or 98 feet), ASTER 15 meters (about 49 feet) Date Acquired: February 2000 (SRTM), June 29, 2001 (ASTER) |
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Uplift and Subsidence Associ
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PIA02435
Sol (our sun)
ASTER
| Title |
Uplift and Subsidence Associated with the Great Aceh-Andaman Earthquake of 2004 |
| Original Caption Released with Image |
The magnitude 9.2 Indian Ocean earthquake of December 26, 2004, produced broad regions of uplift and subsidence. In order to define the lateral extent and the downdip limit of rupture, scientists from Caltech, Pasadena, Calif., NASA's Jet Propulsion Laboratory, Pasadena, Calif., Scripps Institution of Oceanography, La Jolla, Calif., the U.S. Geological Survey, Pasadena, Calif., and the Research Center for Geotechnology, Indonesian Institute of Sciences, Bandung, Indonesia, first needed to define the pivot line separating those regions. Interpretation of satellite imagery and a tidal model were one of the key tools used to do this. These pre-Sumatra earthquake (a) and post-Sumatra earthquake (b) images of North Sentinel Island in the Indian Ocean, acquired from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra spacecraft, show emergence of the coral reef surrounding the island following the earthquake. The tide was 30 plus or minus 14 centimeters lower in the pre-earthquake image (acquired November 21, 2000) than in the post-earthquake image (acquired February 20, 2005), requiring a minimum of 30 centimeters of uplift at this locality. Observations from an Indian Coast Guard helicopter on the northwest coast of the island suggest that the actual uplift is on the order of 1 to 2 meters at this site. In figures (c) and (d), pre-earthquake and post-earthquake ASTER images of a small island off the northwest coast of Rutland Island, 38 kilometers east of North Sentinel Island, show submergence of the coral reef surrounding the island. The tide was higher in the pre-earthquake image (acquired January 1, 2004) than in the post-earthquake image (acquired February 4, 2005), requiring subsidence at this locality. The pivot line must run between North Sentinel and Rutland islands. Note that the scale for the North Sentinel Island images differs from that for the Rutland Island images. The tidal model used for this study was based on data from JPL's Topex/Poseidon satellite. The model was used to determine the relative sea surface height at each location at the time each image was acquired, a critical component used to quantify the deformation. The scientists' method of using satellite imagery to recognize changes in elevation relative to sea surface height and of using a tidal model to place quantitative bounds on coseismic uplift or subsidence is a novel approach that can be adapted to other forms of remote sensing and can be applied to other subduction zones in tropical regions. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with, critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats, monitoring potentially active volcanoes, identifying crop stress, determining cloud morphology and physical properties, wetlands evaluation, thermal pollution monitoring, coral reef degradation, surface temperature mapping of soils and geology, and measuring surface heat balance. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate. |
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Augustine Volcano, Cook Inle
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PIA02148
Sol (our sun)
ASTER
| Title |
Augustine Volcano, Cook Inlet, Alaska (January 12, 2006) |
| Original Caption Released with Image |
ASTER: January 12, 2006, Landsat: September 17, 2000, Since last spring, the U.S. Geological Survey's Alaska Volcano Observatory (AVO) has detected increasing volcanic unrest at Augustine Volcano in Cook Inlet, Alaska near Anchorage. Based on all available monitoring data, AVO regards that an eruption similar to 1976 and 1986 is the most probable outcome. During January, activity has been episodic, and characterized by emission of steam and ash plumes, rising to altitudes in excess of 9,000 m (30,000 ft), and posing hazards to aircraft in the vicinity. An ASTER image was acquired at 12:42 AST on January 12, 2006, during an eruptive phase of Augustine. The perspective rendition shows the eruption plume derived from the ASTER image data. ASTER's stereo viewing capability was used to calculate the 3-dimensional topography of the eruption cloud as it was blown to the south by prevailing winds. From a maximum height of 3060 m (9950 ft), the plume cooled and its top descended to 1900 m (6175 ft). The perspective view shows the ASTER data draped over the plume top topography, combined with a base image acquired in 2000 by the Landsat satellite, that is itself draped over ground elevation data from the Shuttle Radar Topography Mission. The topographic relief has been increased 1.5 times for this illustration. Comparison of the ASTER plume topography data with ash dispersal models and weather radar data will allow the National Weather Service to validate and improve such models. These models are used to forecast volcanic ash plume trajectories and provide hazard alerts and warnings to aircraft in the Alaska region. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats, monitoring potentially active volcanoes, identifying crop stress, determining cloud morphology and physical properties, wetlands evaluation, thermal pollution monitoring, coral reef degradation, surface temperature mapping of soils and geology, and measuring surface heat balance. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate. Size: Roughly 25 km (15 miles) across, scale varies in this perspective view Location: 59.3 deg. North latitude, 153.4 deg. West longitude Orientation: View from southwest towards the northeast Vertical Exaggeration: 2 Eruption plume and Elevation: 30 m ASTER, (1-arcsecond) Image Data: Landsat bands 7, 4 and 2 Ground Topography Data: SRTM 90 m data, acquired January 2000 Date Acquired: |
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Recent Mars and Earth Dust S
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PIA02807
Sol (our sun)
Mars Orbiter Camera
| Title |
Recent Mars and Earth Dust Storms Compared |
| Original Caption Released with Image |
Spring on Mars...in either hemisphere...is a time for local and regional dust storms. These storms arise as the seasonal carbon dioxide frost cap, which can extend almost half-way to the equator, sublimes in the warming spring environment. Several factors promote these dust storms: * the atmospheric pressure is increasing as carbon dioxide frost CO2 sublimes--higher pressure allows more dust to be suspended, and for a longer time, * the temperature contrast between the frost covered surface and immediately adjacent, recently defrosted surfaces is quite high, creating thermally-generated winds that circulate onto and off of the frost cap edge, * similar, temperature-driven winds arise as sublimation of frost covering sun-facing slopes and dark sandy surfaces deep within the polar region creates intense slope winds away from the higher-standing layered deposits and permanent cap. The roughly circular, polar orbit of the Mars Global Surveyor (MGS) spacecraft affords a view not unlike that seen by low Earth-orbiting environmental satellites. Mars is roughly 6800 km (4226 mi) in diameter, and a 370 km (230 mi) average altitude gives a diameter to altitude ratio for MGS of 18.4:1. For comparison, the SeaStar spacecraft in Earth orbit follows a very similar orbit: it's the diameter to altitude ratio is 17.5:1 (12,760 km or 7,928 mi diameter relative to a 705 km or 438 mi altitude). Each spacecraft covers the entire planet in 12 orbits. In this figure, we compare a recent dust storm on Mars with one that occurred earlier this year on Earth. The top image shows a martian north polar dust storm observed on 29 August 2000. This image is part of the Mars Orbiter Camera (MOC) daily global map--a low resolution, two-color view of Mars acquired from pole to pole every orbit. The storm is moving as a front, outward from a central "jet," and marginal "vortices" can be seen. In this image it extends about 900 km (560 mi) out from the north polar seasonal frost cap. The region on the right side of the Mars picture includes the north pole. The bottom image shows a terrestrial dust storm, seen in a SeaWiFS [ http://seawifs.gsfc.nasa.gov/SEAWIFS/IMAGES/SEAWIFS_GALLERY.html ], image, acquired on 26February 2000. This storm extends about 1800 km (1100 mi) off the coast of northwest Africa near the Earth's equator. Both images are shown at the same scale, 4 km (2.5 mi) per pixel. Dust storms play an important role in governing the climate of Mars. The rare, global storms alter the planet's total heat balance and promote variations in seasonal frost formation and dissipation, and greatly affect the distribution of water vapor. Local and regional storms, especially those in the polar regions, affect the rate at which seasonal frost evolves, and control local and regional weather patterns. On Earth, dust storms are also being recognized as contributing to environmental change, potentially influencing seasonal meteorology and the health of biological communities. |
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Shaded Relief with Height as
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PIA03359
Sol (our sun)
C-Band Interferometric Radar
| Title |
Shaded Relief with Height as Color, Iturralde Structure, Bolivia |
| Original Caption Released with Image |
An 8-kilometer (5-mile) wide crater of possible impact origin is shown in this view of an isolated part of the Bolivian Amazon from the Shuttle Radar Topography Mission. The circular feature at the center-left of the image, known as the Iturralde Structure, is possibly the Earth's most recent "big" impact event recording collision with a meteor or comet that might have occurred between 11,000 and 30,000 years ago. Although the structure was identified on satellite photographs in the mid-1980s, its location is so remote that it has only been visited by scientific investigators twice, most recently by a team from NASA's Goddard Space Flight Center in September 2002. Lying in an area of very low relief, the landform is a quasi-circular closed depression only about 20 meters (66 feet) in depth, with sharply defined sub-angular "rim" materials. It resembles a "cookie cutter" in that its appearance "cuts" the heavily vegetated soft-sediments and pampas of this part of Bolivia. The SRTM data have provided investigators with the first topographic map of the site and will allow studies of its three-dimensional structure crucial to determining whether it actually is of impact origin. Two visualization methods were combined to produce this image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the northwest-southeast direction. North-facing slopes appear bright and south-facing slopes appear dark. Color coding is directly related to topographic height, with brown and green at the lower elevations, rising through yellow and brown to white at the highest elevations. Elevation data used in this image was acquired by the Shuttle Radar Topography Mission aboard Space Shuttle Endeavour, launched on Feb. 11, 2000. The mission used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Endeavour in 1994. The Shuttle Radar Topography Mission was designed to collect 3-D measurements of Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Size: 1 degree latitude by 1 degree longitude (about 111 by 111 kilometers or 69 by 69 miles) Location: 12.5 degrees South latitude, 67.5 degrees West longitude Orientation: North at top Image: Elevation data, colored height with shaded relief Original Data Resolution: SRTM 1 arcsecond (about 30 meters or 98 feet) Date Acquired: February 2000 (SRTM) |
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Anaglyph: Shaded Relief and
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PIA03362
Sol (our sun)
C-Band Interferometric Radar
| Title |
Anaglyph: Shaded Relief and Height as Brightness, Iturralde Structure, Bolivia |
| Original Caption Released with Image |
An 8-kilometer (5-mile) wide crater of possible impact origin is shown in this anaglyph view of an isolated part of the Bolivian Amazon derived from a Shuttle Radar Topography Mission (SRTM) elevation model. The circular feature at the center of the image, known as the Iturralde Structure, is possibly the Earth's most recent "big" impact event recording collision with a meteor or comet that might have occurred between 11,000 and 30,000 years ago. Although the structure was identified on satellite photographs in the mid-1980s, its location is so remote that it has only been visited by scientific investigators twice, most recently by a team from NASA's Goddard Space Flight Center in September 2002. Lying in an area of very low relief, the landform is a quasi-circular closed depression only about 20 meters (66 feet) in depth, with sharply defined sub-angular "rim" materials. It resembles a "cookie cutter" in that its appearance "cuts" the heavily vegetated soft-sediments and pampas of this part of Bolivia. The SRTM data have provided investigators with the first topographic map of the site and will allow studies of its three-dimensional structure crucial to determining whether it actually is of impact origin. Thick vegetation in part defines the surface that the SRTM radar sees as it maps the terrain. Much of the local "topography" in this area is a measure of tree height (typically up to 13 meters, or 40 feet). This effect is easily seen here, where the ground surface relief is very low. Interpretative separation of the ground surface and vegetative features typically relies upon recognition of their characteristic patterns. This anaglyph was created by deriving an image of the terrain from the SRTM data, draping it back over the SRTM elevation model, and then generating two differing perspectives, one for each eye. The terrain image depicts a combination of topographic shading (north slopes bright) and topographic height (higher elevations bright). When viewed through special glasses, the anaglyph is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter. Elevation data used in this image was acquired by the Shuttle Radar Topography Mission aboard Space Shuttle Endeavour, launched on Feb. 11, 2000. The mission used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Endeavour in 1994. The Shuttle Radar Topography Mission was designed to collect 3-D measurements of Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense, and the German and Italian space agencies. It is, managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. Size: 0.33 degrees latitude by 0.33 degrees longitude (about 37 by 36 kilometers or 23 by 22 miles) Location: 12.6 degrees South latitude, 67.7 degrees West longitude Orientation: North at top, Latitude-Longitude Projection Original Data Resolution: SRTM 1 arcsecond (about 30 meters or 98 feet) Date Acquired: February 2000 (SRTM) |
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