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Grace and Beauty
Description Our robotic explorer Cassini regards the shadow-draped face of Saturn.
Full Description Our robotic explorer Cassini regards the shadow-draped face of Saturn. This view looks toward the unilluminated side of the rings from about 14 degrees above the ringplane. In this viewing geometry all of the main rings, except for the B ring, appear transparent. The rings cast their mirror image onto the planet beyond. Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were acquired with the Cassini spacecraft wide-angle camera on June 9, 2007, at a distance of approximately 1.6 million kilometers (972,000 miles) from Saturn. Image scale is 90 kilometers (56 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute
Date October 15, 2007
A-25541
Date: Aug 4, 1959 Photograph …
8/4/59
Description Date: Aug 4, 1959 Photograph by NASA/AMES FLIGHT RESEARCH BRANCH PERSONNEL-1959. FRONT ROW: George Rathert, Stu Brown, Norm McFadden, Howard Turner, Gus Brunner, Venia McCloud, Violet Shaw, Kay Rizzi, Yvonne Settle, Genevieve Ziegler, Anita Palmer, Grace Carpenter, Evelyn Olson. SECOND ROW: Bill Triplett, Alan Faye, Dick Bray, Seth Anderson, Steve Belsley, Hervey Quigley, Hank Cole, Elwood Stewart, Don Higdon, Maurie White, Dorothea Wilkinson, Dick Vomaske, Stew Rolls, Mel Sadoff, Mary Thompson, Brent Creer. BACK ROW: Ron Gerdes, Joe Douvillier, John Stewart, Rod Wingrove, Walter McNeill. Note: Used in publication in Flight Research at Ames, 57 Years of Development and Validation of Aeronautical Technology NASA SP-1998-3300 fig 89
Date 8/4/59
ACD01-0184-01
CFC Awards ceremony: Grace A …
11/14/01
Description CFC Awards ceremony: Grace Ann Weiler (L) Ames 2001 CFC chairperson and Nilou Nouri, campaign manager for Santa Clara/San Benito Counties Combined Federal Campaign
Date 11/14/01
ACD01-0184-03
CFC Awards ceremony: (L) Bil …
11/14/01
Description CFC Awards ceremony: (L) Bill Berry, Grace Ann Weiler (C) Ames 2001 CFC chairperson and "Skip" Fletcher, Aerospace Directorate.
Date 11/14/01
ACD01-0184-04
CFC Awards ceremony: William …
11/14/01
Description CFC Awards ceremony: William, Ames Deputy Director (L) Grace Ann Weiler, Ames 2001 CFC chairperson (C) and Tom Moyles, Director of Center Operations accepts CFC Inter-Directorate Competition Outstanding Participation plaque .
Date 11/14/01
ACD02-0106-1
Acquisition Division (Code-J …
6/12/02
Description Acquisition Division (Code-JA) staff : Seated L-R, Julie Donley, Connie Cunningham, Grace Ann Weiler, Standing Back L-R, Gene Moses, Charles Duff
Date 6/12/02
A Spaceborne Perspective on …
Title A Spaceborne Perspective on the Red, White, and Blue
Description Philadelphia, where the Declaration of Independence was signed 225 years ago on July 4, 1776, lies in the center of this image from NASA's Multi-angle Imaging SpectroRadiometer (MISR). This true-color view of the northeastern United States, taken from the instrument's nadir, or downward-looking, camera includes a fitting display of the reddish colors of soils, grayish-whites of urban areas and clouds, and blue hues of water. Larger cities, including New York, Newark, Philadelphia, Wilmington, Baltimore and Washington D.C., are visible from upper right to lower left. The bright sands of the New Jersey shoreline and a pattern of highly reflective roads and bridges extend northward along the coast from Delaware Bay. A popular tourist destination for those wanting to avoid the crowds and main roads is the Coastal Heritage Trail, a 440-kilometer collection of historic and other points of interest developed by the National Park Service and the state of New Jersey. A portion of Pennsylvania's Appalachian Mountains are captured in the upper left corner. The effects of folding and erosion on these ancient, mostly sedimentary deposits are visible, and the reddish colors indicate ironstone and iron-rich sandstone. The southeast-flowing Susquehanna River cuts transversely across these folded formations toward the Chesapeake Bay in Havre de Grace, Maryland, where it provides 50 percent of all the freshwater entering the great estuary. The waters of the Susquehanna originate at Otsego Lake in New York and meander along 700 kilometers until reaching Chesapeake Bay and the sea. This image was acquired on October 11, 2000. It covers an area 334 kilometers x 328 kilometers. North is at the top. Image credit: NASA/GSFC/LaRC/JPL, MISR Team. [ http://www-misr.jpl.nasa.gov/ ]
Mass Concentration in Antarc …
Title Mass Concentration in Antarctica
Description Compared to electricity or magnetism, gravity is a weak force, yet it affects objects as large as oceans, stars, and galaxies. Earth's gravity is not uniform all over the planet. The planet's valleys, ocean trenches, plains, and mountain peaks cause variations in the density of the Earth's surface and, consequently, its gravity field. Launched on March 17, 2002, NASA's Gravity Recovery and Climate Experiment (GRACE) [ http://www.csr.utexas.edu/grace/ ] takes detailed measurements of Earth's gravity field from space. GRACE consists of two satellites that assess differences in Earth's gravity field by tracking tiny changes in their distance from each other. Areas on Earth with greater gravity—known as mass concentrations—pull the leading GRACE satellite away from the trailing satellite. In June 2006, researchers at Ohio State University announced that GRACE had found a mass concentration under the ice in East Antarctica. This image shows GRACE's measurements of gravity, indicated in galileos [ http://en.wikipedia.org/wiki/Gal_(unit) ] per meter. Areas with more intense gravity appear in red, and areas with less intense gravity appear in blue. Yellow and green show levels in between these extremes. Not far from the coast is a 320-kilometer-wide mass concentration, outlined in white. This spot attracted the researchers's attention. The mass concentration GRACE detected indicates an area containing unusually dense material. Such mass concentrations can result from more than one cause. One possible explanation is an upwelling of volcanic rock from deep within Earth's crust. Ralph von Frese, a geology professor at Ohio State University, proposed that the mass concentration may have resulted from an asteroid impact. Approximately 251 million years ago, our planet experienced the worst extinction in its history. Called the Permo-Triassic extinction, this event was far more destructive than the extinction event 65 million years ago that ended the Age of the Dinosaurs. An asteroid impact is widely believed to have caused the dinosaur extinction, and a crater that dates to that time is located on the Yucatan Peninsula. Although multiple explanations have been proposed for the earlier, Permo-Triassic extinction, Von Frese supports the view that an asteroid impact caused it, too. According to Von Frese, the mass concentration GRACE detected in Antarctica could be the crater from an asteroid that triggered the Permo-Triassic extinction. GRACE's discovery is just the first step in understanding this mass concentration. More clues can come from a visit to the site, as well as chemical analyses that provide a geologic age for the rocks in that area. If the rocks date to the same time as the Permo-Triassic extinction, GRACE may have made an important discovery about the history of life (and death) on Earth. Images courtesy Pam Frost Gorder, Ohio State University
Tropical Cyclone Grace
Title Tropical Cyclone Grace
Description The MODIS instrument onboard NASA's Aqua spacecraft captured this true-color image of Tropical Cyclone Grace 500 miles east of Mackay and moving to the southeast. According to the Brisbane Weather Bureau, Graces's low pressure was acting alongside a high pressure system over Tasmania resulting in a steep pressure gradient causing gale force winds and high seas along the Queensland coast. Image courtesy Jesse Allen, Earth Observatory Team at NASA GSFC.
Tropical Storm Grace
Title Tropical Storm Grace
Description *animations:* small (516 KB MPEG)largel [ http://earthobservatory.nasa.gov/NaturalHazards/Archive/Aug2003/labor.day.rain.qt ] (2 MB QuickTime) Heavy rains fell over the central US from Kansas to the western Gulf coast over the Labor Day weekend resulting in deadly flooding. A stationary front lying across the central plains provided the focus for abundant rainfall and thunderstorms as Gulf moisture flowed in from the south. During this same period, Tropical Storm Grace came ashore as a minimal tropical storm on the central Texas gulf coast bringing heavy rains to the Houston area. The TRMM-based, near-real time Multi-satellite Precipitation Analysis (MPA) at the NASA Goddard Space Flight Center was able to capture these events. It shows that the heaviest rainfall totals (darker reds) occurred over eastern Kansas, western Missouri and the northeast corner of Oklahoma with a broad area of 6 to 8 inch amounts. Locally, values exceed 9 inches. Flash floods were reported near Emporia, Kansas where several people were swept away in their vehicles along Interstate 35. Grace dumped upwards of 6 inches of rain in and around the Houston area with locally heavier amounts. The crosses and and storm/depresson symbols mark Grace's path. TRMM is a joint mission between NASA and the Japanese space agency, NASDA. Image and animations produced by Hal Pierce (SSAI/NASA GSFC) and caption by Steve Lang (SSAI/NASA GSFC).
Tropical Storm Grace
Title Tropical Storm Grace
Description *animations:* small (516 KB MPEG)largel [ http://earthobservatory.nasa.gov/NaturalHazards/Archive/Aug2003/labor.day.rain.qt ] (2 MB QuickTime) Heavy rains fell over the central US from Kansas to the western Gulf coast over the Labor Day weekend resulting in deadly flooding. A stationary front lying across the central plains provided the focus for abundant rainfall and thunderstorms as Gulf moisture flowed in from the south. During this same period, Tropical Storm Grace came ashore as a minimal tropical storm on the central Texas gulf coast bringing heavy rains to the Houston area. The TRMM-based, near-real time Multi-satellite Precipitation Analysis (MPA) at the NASA Goddard Space Flight Center was able to capture these events. It shows that the heaviest rainfall totals (darker reds) occurred over eastern Kansas, western Missouri and the northeast corner of Oklahoma with a broad area of 6 to 8 inch amounts. Locally, values exceed 9 inches. Flash floods were reported near Emporia, Kansas where several people were swept away in their vehicles along Interstate 35. Grace dumped upwards of 6 inches of rain in and around the Houston area with locally heavier amounts. The crosses and and storm/depresson symbols mark Grace's path. TRMM is a joint mission between NASA and the Japanese space agency, NASDA. Image and animations produced by Hal Pierce (SSAI/NASA GSFC) and caption by Steve Lang (SSAI/NASA GSFC).
Earth's Shrinking Antarctic …
Title Earth's Shrinking Antarctic Ice Sheet
Explanation Is the continent at the end of the Earth slowly melting? For millions of years, Antarctica [ http://antwrp.gsfc.nasa.gov/apod/ap991116.html ], the frozen continent at the southern end of planet Earth, has been encased in a gigantic sheet [ http://www.pbs.org/wgbh/nova/ice/chill.html ] of ice. Recently, the orbiting robotic GRACE satellite [ http://www.csr.utexas.edu/grace/ ] has been taking sensitive measurements of the gravity [ http://antwrp.gsfc.nasa.gov/apod/ap030723.html ] for the entire Earth, including Antarctica [ http://en.wikipedia.org/wiki/Antarctica ]. Recent analysis [ http://www.jpl.nasa.gov/news/news.cfm?release=2006-028 ] of Gravity Recovery and Climate Experiment [ http://en.wikipedia.org/wiki/Gravity_Recovery_and_Climate_Experiment ] (GRACE) data indicate that the Antarctic ice sheet [ http://en.wikipedia.org/wiki/Antarctic_Ice_Sheet ] might have lost enough mass to cause the worlds' oceans to rise about 1.2 millimeters, on the average, from between 2002 and 2005. Although this may not seem like much, the equivalent amount of water is about 150 trillion liter [ http://en.wikipedia.org/wiki/Liter ]s, equivalent to the amount of water used by US residents [ http://asuwlink.uwyo.edu/~mthomas/ ] in three months. Uncertainties in the measurement make the mass loss uncertain by about 80 trillion liters. Pictured above [ http://www.jpl.nasa.gov/news/news.cfm?release=2006-028 ] is an iceberg [ http://express.howstuffworks.com/wq-iceberg.htm ] that is a small part of the Antarctic ice sheet [ http://antwrp.gsfc.nasa.gov/apod/ap050223.html ]. The picture was taken on the Riiser-Larsen ice shelf in December 1995. Future research will likely focus on trying to better understand the data, take more data, predict future trends, and understand possible effects [ http://www.epa.gov/globalwarming/kids/gw.html ] of these trends on the future climate [ http://www.giss.nasa.gov/edu/gwdebate/ ] of our entire home planet [ http://antwrp.gsfc.nasa.gov/apod/ap050102.html ].
Comet Holmes from the Hubble …
Title Comet Holmes from the Hubble Space Telescope
Explanation Why did Comet Holmes brighten? The unexpectedly bright Comet 17P/Holmes [ http://en.wikipedia.org/wiki/Comet_Holmes ] continues to grace northern skies as a naked-eye addition [ http://cfa-www.harvard.edu/iau/icq/CometMags.html#0017P ] to the constellation Perseus. Any northern sky enthusiast [ http://antwrp.gsfc.nasa.gov/apod/ap040808.html ] with a dark sky [ http://antwrp.gsfc.nasa.gov/apod/ap070508.html ], a bright curiosity [ http://upload.wikimedia.org/wikipedia/commons/thumb/b/b2/ Curiosity.jpg/788px-Curiosity.jpg ], and a recent sky map [ http://en.wikipedia.org/wiki/ Image:Comet_Holmes_simulation_120_days.gif ] should still be able to locate the comet [ http://spaceweather.com/images2007/05nov07/ skymap_north_holmes.gif ] in a few minutes. What is seen, however, is primarily the sun-light reflecting dust coma [ http://www.nasa.gov/worldbook/comet_worldbook.html ]. It surrounds an iceberg nucleus [ http://antwrp.gsfc.nasa.gov/apod/ap000805.html ] too small and too faint to discern. Clues to the nearly million-fold brightness increase [ http://antwrp.gsfc.nasa.gov/apod/ap071026.html ] are therefore being sought in dramatic images of the enigmatic comet's central regions taken earlier this month by the Hubble Space Telescope [ http://www.stsci.edu/hst/HST_overview/ ]. One such Hubble image, shown above [ http://hubblesite.org/newscenter/archive/releases/2007/ 40/image/a/ ], indicates a still unresolved dense central dust cloud near the nucleus [ http://antwrp.gsfc.nasa.gov/apod/ap040103.html ], surrounded by a more complex, anisotropic coma. The Hubble images [ http://hubblesite.org/newscenter/archive/releases/2007/ 40/image/a/ ] do not show any obvious fragmentation [ http://antwrp.gsfc.nasa.gov/apod/ap010521.html ] of the nucleus, however, as was seen last year in Comet Schwassman-Wachmann 3 [ http://antwrp.gsfc.nasa.gov/apod/ap060504.html ]. Observers around and above the world will continue to study this unusual addition to the night sky [ http://antwrp.gsfc.nasa.gov/apod/ap071117.html ].
A Gravity Map of Earth
Title A Gravity Map of Earth
Explanation Is gravity [ http://www.curtin.edu.au/curtin/dept/phys-sci/gravity/history/history.htm ] the same over the surface of the Earth [ http://antwrp.gsfc.nasa.gov/apod/ap001127.html ]? No -- it turns out that in some places you will feel slightly heavier [ http://www.nyu.edu/pages/mathmol/textbook/weightvmass.html ] than others. The above relief map [ http://www.jpl.nasa.gov/earth/features/watkins.html ] shows in exaggerated highs and lows where the gravitational field [ http://csep10.phys.utk.edu/astr161/lect/history/newtongrav.html ] of Earth [ http://antwrp.gsfc.nasa.gov/apod/ap010204.html ] is relatively strong and weak. A low spot can be seen just off the coast of India [ http://www.cia.gov/cia/publications/factbook/geos/in.html ], while a relative high occurs in the South Pacific Ocean [ http://www.cia.gov/cia/publications/factbook/geos/zn.html ]. The cause of these irregularities is unknown since present surface features do not appear dominant. Scientists hypothesize [ http://science.nasa.gov/headlines/y2001/ast30oct_1.htm ] that factors that are more important lay in deep underground structures [ http://www.thetech.org/exhibits_events/online/quakes/inside/mantle.html ] and may be related to the Earth's appearance in the distant past [ http://www.scotese.com/earth.htm ]. To better map Earth's gravity [ http://www.agu.org/revgeophys/nerem01/node3.html ] and hence better understand its interior [ http://www.solarviews.com/eng/earthint.htm ] and past, NASA [ http://www.nasa.gov/ ] plans to launch the Gravity Recovery and Climate [ http://essp.gsfc.nasa.gov/grace/ ] (GRACE) satellite in February.
If You Could Stand on Mars
Title If You Could Stand on Mars
Explanation If you could stand on Mars [ http://antwrp.gsfc.nasa.gov/apod/ap960721.html ] - what would you see? Viking 1 robot landers answered this question in 1976 with pictures like the one shown above. The dark rocks, red soil, and green-tinged sky grace this rendition [ http://barsoom.msss.com/mars/pictures/viking_lander/ viking_lander.html ] of a normal Martian [ http://seds.lpl.arizona.edu/nineplanets/nineplanets/mars.html ] afternoon. At the bottom corners of the picture are portions of Viking spacecraft. The red color of the rocks is caused by an abundance of iron in the soil. The Martian [ http://nssdc.gsfc.nasa.gov/photo_gallery/PhotoGallery-Mars.html ] surface is covered by rocks, huge craters [ http://antwrp.gsfc.nasa.gov/apod/ap960203.html ], fantastic canyons [ http://antwrp.gsfc.nasa.gov/apod/ap950720.html ], and gigantic volcanoes [ http://antwrp.gsfc.nasa.gov/apod/ap950719.html ] that dwarf any on Earth [ http://antwrp.gsfc.nasa.gov/apod/ap951216.html ]. No life has been found, but some speculate that since not all spacecraft reaching Mars [ http://cmex-www.arc.nasa.gov/ ] from Earth [ http://antwrp.gsfc.nasa.gov/apod/ap950824.html ] had been fully decontaminated [ http://cmex-www.arc.nasa.gov/Exo_Strat/Docs/protection.html ], Earth born microbes [ http://www.discovery.com/DCO/doc/1012/world/nature/deceit/deceit4.1.html ] might live there now [ http://commtechlab.msu.edu/CTLProjects/dlc-me/news/ns1095ap4.html ].
GRACE Maps the Gravity of Ea …
Title GRACE Maps the Gravity of Earth
Explanation Why do some places on Earth have higher gravity than others? Sometimes the reason is unknown. To help better understand the Earth's surface [ http://www.windows.ucar.edu/tour/link=/earth/Interior_Structure/surface.html ], slight distance changes between a pair of identically orbiting satellites named GRACE [ http://antwrp.gsfc.nasa.gov/apod/ap030723.html http://essp.gsfc.nasa.gov/grace/ ] have been used to create the best ever map of Earth's gravitational field [ http://www.curtin.edu.au/curtin/dept/phys-sci/gravity/history/history.htm ]. High points on this map [ http://www.csr.utexas.edu/grace/gallery/animations/ggm01/ ], also colored red, indicate areas where gravity is slightly stronger than usual, while in blue areas gravity is slightly weaker. Many bumps and valleys on the map can be attributed to surface features, such as the North Mid-Atlantic Ridge [ http://www.wikipedia.org/wiki/Mid-Atlantic_Ridge ] and the Himalayan Mountains [ http://antwrp.gsfc.nasa.gov/apod/ap020723.html ], but others cannot, and so might relate to unusually high or low sub-surface densities. Maps like this [ http://photojournal.jpl.nasa.gov/catalog/PIA04652 ] also help calibrate changes in the Earth's surface including variable ocean currents [ http://antwrp.gsfc.nasa.gov/apod/ap980113.html ] and the melting of glaciers [ http://antwrp.gsfc.nasa.gov/apod/ap020527.html ].
Moon and Planets Sky Credit …
Title Moon and Planets Sky Credit & Copyright: Wojtek Rychlik [ http://www.pikespeakphoto.com ]
Explanation Look up into the sky tonight [ http://science.nasa.gov/headlines/y2004/ 19mar_planets.htm ] and without a telescope or binoculars you might have a view [ http://astronomy.swin.edu.au/staff/gmackie/billions.html ] like this one of Moon, planets and stars. The lovely photo [ http://www.pikespeakphoto.com/planets.html ] was taken on March 23rd, and captures the crescent Moon on the horizon with Venus above it. Both brilliant celestial bodies are over-exposed. Farther above Venus is the tinted glow of Mars with the Pleiades star cluster just to the red planet's right. The V-shaped arrangement of stars [ http://antwrp.gsfc.nasa.gov/apod/ap040304.html ] to the left of Mars is the Hydaes star cluster. Bright red giant Aldebaran [ http://www.astro.uiuc.edu/~kaler/sow/ aldebaran.html ], not itself a member of the Hyades cluster, marks the top left of the V. During the next week [ http://www.griffithobs.org/planetsgather.html ], all five naked-eye planets, Mercury, Venus, Mars, Jupiter, and Saturn, along with the Moon will grace the evening sky [ http://skyandtelescope.com/observing/objects/planets/ article_1226_1.asp ] together - a lunar and planetary spectacle that can be enjoyed by skygazers [ http://www.spaceweather.com/ ] around the world. But look just after sunset, low on the western horizon, to see Mercury [ http://antwrp.gsfc.nasa.gov/apod/ap030412.html ] before it sets. The next similar gathering [ http://antwrp.gsfc.nasa.gov/apod/ap000524.html ] of the planets will be in 2008.
Planets in the West
Title Planets in the West
Explanation This week [ http://www.griffithobs.org/skyreport.html ]end three planets will grace the western sky [ http://science.nasa.gov/headlines/y2005/ 22jun_spectacular.htm ], forming a lovely trio easily visible shortly after sunset. Saturday evening in particular will find Saturn [ http://soc.jpl.nasa.gov/index.cfm ], Venus [ http://www.space.com/spacewatch/ 050513_venus_returns.html ], and Mercury [ http://www.fourmilab.ch/images/3planets/ elongation.html ] all within a 2 degree circle (about the size of your thumb held at arm's length) above the western horizon. Recorded last Sunday, June 19, this image shows the same three planets arrayed along the ecliptic plane [ http://antwrp.gsfc.nasa.gov/apod/ap040501.html ] above a Colorado Rocky Mountain skyline. Venus is easiest to pick out of the twilight, the brightest celestial beacon below picture center, with Saturn above and to the left of Venus, and Mercury closest to the horizon, right of prominent Pinnacle Peak. By Saturday [ http://skyandtelescope.com/observing/ataglance/ article_110_1.asp ], the wandering planets [ http://spacekids.hq.nasa.gov/osskids/ animate/mac.html ] will draw even closer together. For help spotting the planets here, put your cursor over the picture.
NGC 1 and NGC 2
Title NGC 1 and NGC 2
Explanation Beautiful nebulae [ http://antwrp.gsfc.nasa.gov/apod/ap050303.html ], clusters [ http://antwrp.gsfc.nasa.gov/apod/ap031215.html ], and galaxies [ http://antwrp.gsfc.nasa.gov/apod/ap050112.html ] that grace planet Earth's night sky are often known by their New General Catalog designation or NGC number [ http://www.ngcic.org/ ]. That classic listing was compiled by John Louis Emil Dreyer [ http://star.arm.ac.uk/history/dreyer.html ], remarkable director of the Armagh Observatory [ http://star.arm.ac.uk/ ] from 1882 to 1916. NGC 2266 is [ http://antwrp.gsfc.nasa.gov/apod/ap050319.html ], for example, the 2,266th item in his New General Catalog of Nebulae and Clusters of Stars. Noting that "every book [ http://www.ngcic.org/legacy/ ngconline/default.htm ] has a first page", modern day astronomer Jay GaBany wondered what NGC 1 might look like - and found it [ http://www.ngcic.org/DSS/dss_n0001.asp ], along with NGC 2 in the constellation Pegasus. Pictured above, both are more or less typical-sized (50-100 thousand light-years across) spiral galaxies [ http://csep10.phys.utk.edu/astr162/lect/galaxies/ spiral.html ] with estimated distances of over 150 million light-years for NGC 1 (top) and about twice that for NGC 2. NGC ordering is based on an astronomical coordinate system [ http://physics.gmu.edu/~jevans/astr103/CourseNotes/ earthSky_coordinateSystems.html ], so these otherwise unremarkable spirals appear first in the NGC listing because their location in the sky translates to the smallest Right Ascension [ http://condor.stcloudstate.edu/~physcrse/astr106/ra.html ] coordinate in the catalog.
Sun Block
Title Sun Block
Explanation During a total solar eclipse, Earth's moon blocks the sun [ http://www.exploratorium.edu/eclipse/why.html ] - almost exactly. While the sun is about 400 times wider than the moon, it is also about 400 times farther away and each appears to be half a degree or so in diameter. On August 11 [ http://www.skypub.com/sights/eclipses/ee99home.html ], this remarkable coincidence in the apparent size of two vastly different celestial bodies produced tantalizing solar spectacles for denizens of Europe and Asia. For example, prominences along the sun's limb peer around the moon's dark edge in this dramatic picture [ http://friko5.onet.pl/kr/pastdom/zacmie.htm ] of totality recorded as the lunar shadow swept across Hungary. Subtle structures in the sun's inner corona are also visible streaming beyond the silhouetted moon. This total eclipse [ http://www.eclipsecast.com/ ] of the sun was the last to grace planet Earth's skies for this millennium [ http://www.usno.navy.mil/millennium/ ]. Although four partial eclipses [ http://sunearth.gsfc.nasa.gov/eclipse/eclipse.html ] will occur in the year 2000, the next total eclipse [ http://sunearth.gsfc.nasa.gov/eclipse/SEpath/SE2001Jun21T.html ] will not be until 2001 June 21.
Artist's concept of Gravity …
Title Artist's concept of Gravity Recovery and Climate Experiment
Description Artist's concept of Grace
Date 12.21.2002
Artist's concept of Gravity …
Title Artist's concept of Gravity Recovery and Climate Experiment
Description Artist's concept of Grace
Date 12.21.2002
Antarctic Tides: Image of th …
nasa, nasaimageofthedaygalle …
To know whether Antarctic ic …
antarctica_gra_2004
mediatype IMAGE
mediatype image
date 2004
creator NASA -- Images courtesy Ohio State University
identifier antarctica_gra_2004
Antarctic Tides: Image of th …
nasa, nasaimageofthedaygalle …
To know whether Antarctic ic …
antarctica_gra_2004
mediatype IMAGE
mediatype image
date 2004
creator NASA -- Images courtesy Ohio State University
identifier antarctica_gra_2004
Madrid, Spain: Image of the …
nasa, nasaimageofthedaygalle …
Madrid, Spain, is world reno …
madrid_ASTER
mediatype IMAGE
mediatype image
date 2000-07-05
creator NASA -- Image provided by U.S./Japan asterweb.jpl.nasa.gov'' target''outlink ASTER Science Team
identifier madrid_ASTER
Studying Earth's Gravity Fie …
nasa, nasaimageofthedaygalle …
The first image released fro …
global_gra_2002340
mediatype IMAGE
mediatype image
date 2002
creator NASA -- Image courtesy www.csr.utexas.edu/grace/ GRACE Science Team NASA, German Aerospace Center, University of Texas Center for Space Research, and GeoForschungsZentrum Potsdam.
identifier global_gra_2002340
December's Lunar Eclipse Tak …
jplhdvideocollection, nasa
A lunar eclipse and a planet …
whatsup20101201-1280-i
mediatype VIDEO
mediatype movies
date 2010-12-01
creator NASA
identifier whatsup20101201-1280-i
Mass Concentration in Antarc …
nasa, nasaimageofthedaygalle …
Compared to electricity or m …
antarctica_gra_2006
mediatype IMAGE
mediatype image
date 2002-03-17
creator NASA -- Images courtesy Pam Frost Gorder, Ohio State University
identifier antarctica_gra_2006
Earth's Gravity Field: Image …
nasa, nasaimageofthedaygalle …
The joint NASA-German Aerosp …
PIA04652
mediatype IMAGE
mediatype image
date 2003
creator NASA -- Image courtesy NASA Jet Propulsion Laboratory, University of Texas www.csr.utexas.edu/ Center for Space Research, and op.gfz-potsdam.de/ GeoForschungsZentrum Potsdam
identifier PIA04652
Greenland Ice Sheet Losing M …
nasa, nasaimageofthedaygalle …
, in the online edition of t …
grace_greenland_mass_trend
mediatype MISC
mediatype texts
date 2006-10-19
creator NASA -- NASA image courtesy Scott Luthcke
identifier grace_greenland_mass_trend
Greenland Ice Sheet Losing M …
nasa, nasaimageofthedaygalle …
, in the online edition of t …
grace_greenland_mass_trend
mediatype IMAGE
mediatype texts
date 2006-10-19
creator NASA -- NASA image courtesy Scott Luthcke
identifier grace_greenland_mass_trend
The Rising Sea Level: Image …
nasa, nasaimageofthedaygalle …
Rising or falling sea level …
sealevel_jason_200606
mediatype IMAGE
mediatype texts
date 2005
creator NASA -- Graph adapted by Robert Simmon from Leuliette, E., Nerem, R., and Mitchum, G. (2004). Calibration of TOPEX/Poseidon and Jason altimeter data to construct a continuous record of mean sea level change. Marine Geodesy, 27(1-2), 79-94.
identifier sealevel_jason_200606
The Rising Sea Level: Image …
nasa, nasaimageofthedaygalle …
Rising or falling sea level …
sealevel_jason_200606
mediatype MISC
mediatype texts
date 2005
creator NASA -- Graph adapted by Robert Simmon from Leuliette, E., Nerem, R., and Mitchum, G. (2004). Calibration of TOPEX/Poseidon and Jason altimeter data to construct a continuous record of mean sea level change. Marine Geodesy, 27(1-2), 79-94.
identifier sealevel_jason_200606
Cassidy during EVA-5
johnsonspacecentermediaarchi …
View of Christopher Cassidy, …
s127e009350
mediatype IMAGE
mediatype image
date 2009-07-27
creator NASA
identifier s127e009350
NASA and German Space Agency …
nasa, nasahighlightsimagegal …
NASA Deputy Administrator Lo …
463519main_4
mediatype IMAGE
mediatype image
date 2010-06-17
creator NASA
identifier 463519main_4
Cassidy during EVA-5
johnsonspacecentermediaarchi …
View of Christopher Cassidy, …
s127e009349
mediatype IMAGE
mediatype image
date 2009-07-27
creator NASA
identifier s127e009349
Tropical Cyclone Grace: Natu …
nasa, nasanaturalhazards
The MODIS instrument onboard …
aqua_tcgrace_22mar04
mediatype IMAGE
mediatype image
date 2004-03-22
creator NASA -- NASA Image Of The Day
identifier aqua_tcgrace_22mar04
Water Flow in the Amazon: Im …
nasa, nasaimageofthedaygalle …
The Amazon River basin carri …
geoid_gra_2003
mediatype IMAGE
mediatype image
date 2003
creator NASA -- Images courtesy Paul Thompson www.csr.utexas.edu/grace/ GRACE Science Team
identifier geoid_gra_2003
A Spaceborne Perspective on …
nasa, nasaimageofthedaygalle …
Philadelphia, where the Decl …
AnRGB_P014_O4344_phila
mediatype IMAGE
mediatype image
date 2000-10-11
creator NASA -- Image credit: NASA/GSFC/LaRC/JPL, www-misr.jpl.nasa.gov/ MISR Team.
identifier AnRGB_P014_O4344_phila
Retreating Ice and Snow in G …
nasa, nasaimageofthedaygalle …
In October 2006, a study usi …
segreenland_tmo_2006242
mediatype IMAGE
mediatype image
date 2006-08-30
creator NASA -- NASA image by Jesse Allen, Earth Observatory. Image interpretation provided by Ian Joughin, University of Washington, and Ted Scambos, National Snow and Ice Data Center.
identifier segreenland_tmo_2006242
Tropical Storm Grace: Natura …
nasa, nasanaturalhazards
animations: /NaturalHazards/ …
grace_trm2003245
mediatype IMAGE
mediatype image
date 2003-09-02
creator NASA -- NASA Image Of The Day
identifier grace_trm2003245
Susquehanna River: Image of …
nasa, nasaimageofthedaygalle …
After carving its way throug …
susquehanna_etm_1999266
mediatype IMAGE
mediatype image
date 2005
creator NASA -- NASA image by Robert Simmon, based on landsat.gsfc.nasa.gov/ Landsat-7 data provided by the UMD glcf.umiacs.umd.edu/index.shtml Global Land Cover Facility
identifier susquehanna_etm_1999266
Water Storage Anomalies in M …
nasa, nasaimageofthedaygalle …
Seasonal variations in preci …
Missanomaly_GRA_2005
mediatype IMAGE
mediatype image
date 2005
creator NASA -- Images created by Ben Zaitchik and Matt Rodell, Hydrological Sciences Branch, NASA Goddard Space Flight Center.
identifier Missanomaly_GRA_2005
Earthquake Signal Visible in …
PIA03625
Sol (our sun)
K-Band Ranging System
Title Earthquake Signal Visible in GRACE Data
Original Caption Released with Image Figure1 This figure shows the effect of the December 2004 great Sumatra earthquake on the Earth?s gravity field as observed by GRACE. The signal is expressed in terms of the relative acceleration of the two GRACE satellites, in this case a few nanometers per second squared, or about 1 billionth of the acceleration we experience everyday at the Earth?s surface.GRACE observations show comparable signals in the region of the earthquake. Other natural variations are also apparent in the expected places, whereas no other significant change would be expected in the region of the earthquake GRACE, twin satellites launched in March 2002, are making detailed measurements of Earth's gravity field which will lead to discoveries about gravity and Earth's natural systems. These discoveries could have far-reaching benefits to society and the world's population.
Earthquake Signal Visible in …
PIA03625
Sol (our sun)
K-Band Ranging System
Title Earthquake Signal Visible in GRACE Data
Original Caption Released with Image Figure1 This figure shows the effect of the December 2004 great Sumatra earthquake on the Earth?s gravity field as observed by GRACE. The signal is expressed in terms of the relative acceleration of the two GRACE satellites, in this case a few nanometers per second squared, or about 1 billionth of the acceleration we experience everyday at the Earth?s surface.GRACE observations show comparable signals in the region of the earthquake. Other natural variations are also apparent in the expected places, whereas no other significant change would be expected in the region of the earthquake GRACE, twin satellites launched in March 2002, are making detailed measurements of Earth's gravity field which will lead to discoveries about gravity and Earth's natural systems. These discoveries could have far-reaching benefits to society and the world's population.
Artist's concept of Gravity …
PIA04236
Title Artist's concept of Gravity Recovery and Climate Experiment
Original Caption Released with Image Artist's concept of Grace
Artist's concept of Gravity …
PIA04235
Title Artist's concept of Gravity Recovery and Climate Experiment
Original Caption Released with Image Artist's concept of Grace
A Spaceborne Perspective on …
PIA03412
Sol (our sun)
Multi-angle Imaging SpectroR …
Title A Spaceborne Perspective on the Red, White, and Blue
Original Caption Released with Image Philadelphia, where the Declaration of Independence was signed 225 years ago on July 4, 1776, lies in the center of this image from NASA's Multi-angle Imaging SpectroRadiometer (MISR). This true-color view of the northeastern United States, taken from the instrument's nadir, or downward-looking, camera includes a fitting display of the reddish colors of soils, grayish-whites of urban areas and clouds, and blue hues of water. Larger cities, including New York, Newark, Philadelphia, Wilmington, Baltimore and Washington D.C., are visible from upper right to lower left. The bright sands of the New Jersey shoreline and a pattern of highly reflective roads and bridges extend northward along the coast from Delaware Bay. A popular tourist destination for those wanting to avoid the crowds and main roads is the Coastal Heritage Trail, a 440-kilometer collection of historic and other points of interest developed by the National Park Service and the state of New Jersey. A portion of Pennsylvania's Appalachian Mountains are captured in the upper left corner. The effects of folding and erosion on these ancient, mostly sedimentary deposits are visible, and the reddish colors indicate ironstone and iron-rich sandstone. The southeast-flowing Susquehanna River cuts transversely across these folded formations toward the Chesapeake Bay in Havre de Grace, Maryland, where it provides 50 percent of all the freshwater entering the great estuary. The waters of the Susquehanna originate at Otsego Lake in New York and meander along 700 kilometers until reaching Chesapeake Bay and the sea. This image was acquired on October 11, 2000, during Terra orbit 4344. It covers an area 334 kilometers x 328 kilometers. North is at the top. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.
New Views of Earth's Gravity …
PIA04652
Sol (our sun)
K-Band Ranging System
Title New Views of Earth's Gravity Field from GRACE
Original Caption Released with Image Gravity and the Earth's Shape Gravity is the force that is responsible for the weight of an object and is determined by how the material that makes up the Earth is distributed throughout the Earth. Because gravity changes over the surface of the Earth, the weight of an object changes along with it. One can define standard gravity as the value of gravity for an perfectly smooth 'idealized' Earth, and the gravity 'anomaly' is a measure of how actual gravity deviates from this standard. Gravity reflects the Earth's surface topography to a high degree and is associated with features that most people are familiar with such as large mountains and deep ocean trenches. Progress in Measuring the Earth's Gravity Field Through GRACE Prior to GRACE, the Earth's gravity field was determined using measurements of varying quality from different satellites and of incomplete coverage. Consequently the accuracy and resolution of the gravity field were limited. As is shown in Figure 1, the long wavelength components of the gravity field determined from satellite tracking were limited to a resolution of approximately 700 km. At shorter wavelengths, the errors were too large to be useful. Only broad geophysical features of the Earth's structure could be detected (see map 1). In contrast, GRACE, by itself, has provided accurate gravity information with a resolution of 200 km. Now, much more detail is clearly evident in the Earth's geophysical features (see map 2). High resolution features detected by GRACE that are representative of geophysical phenomena include the Tonga/Kermadec region (a zone where one tectonic plate slides under another), the Himalayan/Tibetan Plateau region (an area of uplift due to colliding plates), and the mid-Atlantic ridge (an active spreading center in the middle of the Atlantic ocean where new crust is being created). Future GRACE gravity models are expected to increase the resolution further. The second figure confirms that the Grace data is global, homogeneous and highly accurate. These are all properties that have been sought for gravity model development., Ocean Circulation Measurements from Grace The arrows in the three data sets in Figure 3 depict ocean currents off the East Coast of the United States, 1,000 meters (approximately 3,280 feet) beneath the surface. The top panel is obtained from the GRACE geoid, satellite altimetry and ship measurements of temperature and salt. The bottom panel is computed in the same manner as the top one, except that the best geoid prior to GRACE is used instead of the GRACE geoid. The middle panel shows direct measurement of those currents by floats deployed from ships. Notice that the current arrows in the Gulf Stream extension, East and slightly South of Washington DC, point eastward, toward Europe, in the two upper panels, but in the opposite direction in the lower panel. Colors indicate the strength of the ocean current, with red being strongest and blue-green weakest. Areas in white have no available data. The Gulf Stream region of the North Atlantic is among the best studied in the world's oceans, with a significant quantity of high-quality data available on it as a result of shipborne instrument measurements. In less well studied regions, the new information provided by GRACE, together with satellite altimetry, will increase our knowledge of ocean circulation.
New Views of Earth's Gravity …
PIA04652
Sol (our sun)
K-Band Ranging System
Title New Views of Earth's Gravity Field from GRACE
Original Caption Released with Image Gravity and the Earth's Shape Gravity is the force that is responsible for the weight of an object and is determined by how the material that makes up the Earth is distributed throughout the Earth. Because gravity changes over the surface of the Earth, the weight of an object changes along with it. One can define standard gravity as the value of gravity for an perfectly smooth 'idealized' Earth, and the gravity 'anomaly' is a measure of how actual gravity deviates from this standard. Gravity reflects the Earth's surface topography to a high degree and is associated with features that most people are familiar with such as large mountains and deep ocean trenches. Progress in Measuring the Earth's Gravity Field Through GRACE Prior to GRACE, the Earth's gravity field was determined using measurements of varying quality from different satellites and of incomplete coverage. Consequently the accuracy and resolution of the gravity field were limited. As is shown in Figure 1, the long wavelength components of the gravity field determined from satellite tracking were limited to a resolution of approximately 700 km. At shorter wavelengths, the errors were too large to be useful. Only broad geophysical features of the Earth's structure could be detected (see map 1). In contrast, GRACE, by itself, has provided accurate gravity information with a resolution of 200 km. Now, much more detail is clearly evident in the Earth's geophysical features (see map 2). High resolution features detected by GRACE that are representative of geophysical phenomena include the Tonga/Kermadec region (a zone where one tectonic plate slides under another), the Himalayan/Tibetan Plateau region (an area of uplift due to colliding plates), and the mid-Atlantic ridge (an active spreading center in the middle of the Atlantic ocean where new crust is being created). Future GRACE gravity models are expected to increase the resolution further. The second figure confirms that the Grace data is global, homogeneous and highly accurate. These are all properties that have been sought for gravity model development., Ocean Circulation Measurements from Grace The arrows in the three data sets in Figure 3 depict ocean currents off the East Coast of the United States, 1,000 meters (approximately 3,280 feet) beneath the surface. The top panel is obtained from the GRACE geoid, satellite altimetry and ship measurements of temperature and salt. The bottom panel is computed in the same manner as the top one, except that the best geoid prior to GRACE is used instead of the GRACE geoid. The middle panel shows direct measurement of those currents by floats deployed from ships. Notice that the current arrows in the Gulf Stream extension, East and slightly South of Washington DC, point eastward, toward Europe, in the two upper panels, but in the opposite direction in the lower panel. Colors indicate the strength of the ocean current, with red being strongest and blue-green weakest. Areas in white have no available data. The Gulf Stream region of the North Atlantic is among the best studied in the world's oceans, with a significant quantity of high-quality data available on it as a result of shipborne instrument measurements. In less well studied regions, the new information provided by GRACE, together with satellite altimetry, will increase our knowledge of ocean circulation.
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