|
|
Browse All
:
Moon of Goddard Space Flight Center (GSFC) from 2006
|
Printer Friendly |
Enceladus Keeps the Home Fir
…
| Description |
Enceladus Keeps the Home Fires Burning |
| Full Description |
On Nov. 9, 2006, Cassini's composite infrared spectrometer captured its first view of the infrared heat radiation emanating from the "tiger stripe" fractures at the south pole of Saturn's moon Enceladus (right) since the discovery of the hot spot 16 months earlier (left). The original discovery was made just before a close flyby of Enceladus on July 14, 2005, and coincided with the discovery of plumes of water-rich gas and ice particles jetting out of the tiger stripes. However, the spacecraft's orbit did not provide any good views of the south pole for follow-up observations until November 2006. The new observations were made from a range of 110,000 kilometers (68,350 miles), slightly more distant than the 80,000-kilometer range (49,700 miles) of the original observations. Comparison of the two images shows that the south polar region continues to be active, and the distribution of temperatures there has changed little in 16 months. The distribution of heat radiation suggests that most or all of the south polar heat comes from the tiger stripes themselves, though the individual stripes are not resolved at the approximate 30-kilometer (19-mile) spatial resolution of these images. The images show the intensity of heat radiation in the 10- to 16-micron wavelength range, translated into temperature and displayed in false color. Peak south polar temperature on both dates reached about 85 Kelvin (minus 306 degrees Fahrenheit), averaged over the 30-kilometer (19-mile) spatial resolution of the data. However, the variation in brightness with wavelength, which is also measured by the composite infrared spectrometer, reveals that the warm region includes small areas, possibly zones a few 100 meters (320 feet) wide along the length of the tiger stripes, that are at higher temperatures, reaching at least 130 Kelvin (minus 225 degrees Fahrenheit) and perhaps much warmer still. While the south polar tiger stripes are almost certainly heated by energy from the moon's interior, daytime regions at low latitudes are warmed by sunlight to temperatures in the high 70s Kelvin (about minus 320 degrees Fahrenheit). The white numbers on the images show west longitudes on Enceladus, which is 500 kilometers (310 miles) in diameter. The dashed line shows the terminator, the boundary between day and night. The blotchy appearance of the cooler regions away from the south pole, and of the sky beyond the globe of Enceladus, is an artifact resulting from the fact that apart from the polar hot spot, the composite infrared spectrometer can barely detect the very faint heat radiation from this very cold moon. 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 was designed, developed and assembled at JPL. The, composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/. The composite infrared spectrometer team homepage is http://cirs.gsfc.nasa.gov/. *Image Credit:* NASA/JPL/GSFC/Southwest Research Institute |
| Date |
December 22, 2006 |
|
Searching for Warmth
| Description |
The exciting mystery of an active south polar region on Saturn's icy moon Enceladus continues to unfold as scientists make the correlation between geologically youthful surface fractures and unusually warm temperatures. |
| Full Description |
The exciting mystery of an active south polar region on Saturn's icy moon Enceladus continues to unfold as scientists make the correlation between geologically youthful surface fractures and unusually warm temperatures. This view shows excess heat radiation from cracks near the moon's south pole. These warm fissures are the source of plumes of dust and gas seen by multiple instruments on the Cassini spacecraft during its flyby of Enceladus on July 14, 2005, as described in a series of papers in the March 10, 2006, issue of the journal Science. This image shows two arrays of temperature readings across the surface of Enceladus, as measured by the Cassini composite infrared spectrometer, superimposed on images of the surface taken simultaneously by the imaging science subsystem. Surface temperatures in Kelvin, derived from the intensity of infrared radiation detected by the composite infrared spectrometer, are shown along with their formal uncertainties, although true uncertainties for temperatures below about 75 Kelvin (minus 325 degrees Fahrenheit) are not easily described by a single number. Enhanced thermal emission is seen in the vicinity of the prominent "tiger stripe" fissures discovered by the imaging cameras. In this image, the excess emission is most strongly seen in the left-most composite infrared spectrometer field of view, which includes a fissure near the end of one of the tiger stripes. The peak temperatures, 86 Kelvin and 90 Kelvin (minus 305 and minus 298 degrees Fahrenheit) respectively, are averages over the composite infrared spectrometer field of view, and other composite infrared spectrometer data suggest that much higher temperatures, up to at least 145 Kelvin (minus 199 degrees Fahrenheit), occur in narrow zones a few hundred meters wide along the tiger stripe fissures. See (PIA07794) for a related image. This image is centered near longitude 135 west, latitude 65 south, and each square from the composite infrared spectrometer field of view is 17.5 kilometers (10.9 miles) across. This Cassini narrow-angle camera image has been cropped and resized for presentation. 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 was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. 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 composite infrared spectrometer team homepage is http://cirs.gsfc.nasa.gov/. The imaging team homepage is at http://ciclops.org *Credit:* NASA/JPL/GSFC/Space Science Institute |
| Date |
March 9, 2006 |
|
Searching for Warmth
| Description |
The exciting mystery of an active south polar region on Saturn's icy moon Enceladus continues to unfold as scientists make the correlation between geologically youthful surface fractures and unusually warm temperatures. |
| Full Description |
The exciting mystery of an active south polar region on Saturn's icy moon Enceladus continues to unfold as scientists make the correlation between geologically youthful surface fractures and unusually warm temperatures. This view shows excess heat radiation from cracks near the moon's south pole. These warm fissures are the source of plumes of dust and gas seen by multiple instruments on the Cassini spacecraft during its flyby of Enceladus on July 14, 2005, as described in a series of papers in the March 10, 2006, issue of the journal Science. This image shows two arrays of temperature readings across the surface of Enceladus, as measured by the Cassini composite infrared spectrometer, superimposed on images of the surface taken simultaneously by the imaging science subsystem. Surface temperatures in Kelvin, derived from the intensity of infrared radiation detected by composite infrared spectrometer, are shown along with their formal uncertainties, although true uncertainties for temperatures below about 75 Kelvin (minus 325 degrees Fahrenheit) are not easily described by a single number. Enhanced thermal emission is seen in the vicinity of the prominent "tiger stripe" fissures discovered by the imaging cameras. In this image, the excess emission is near the center of the composite infrared spectrometer array, directly over a tiger stripe fissure. The peak temperatures, 86 Kelvin and 90 Kelvin (minus 305 and minus 298 degrees Fahrenheit) respectively, are averages over the composite infrared spectrometer field of view, and other composite and infrared spectrometer data suggest that much higher temperatures, up to at least 145 Kelvin (minus 199 degrees Fahrenheit), occur in narrow zones a few hundred meters wide along the tiger stripe fissures. See (PIA07793) for a related image. This image was taken nearly three times closer to the moon and is centered near longitude 120 west, latitude 82 south, and each composite infrared spectrometer field of view is 6.0 kilometers (3.7 miles) across. This Cassini narrow-angle camera image was cropped and resized for presentation. 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 was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. 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 composite infrared spectrometer team homepage is http://cirs.gsfc.nasa.gov/. The imaging team homepage is at http://ciclops.org *Credit:* NASA/JPL/GSFC/Space Science Institute |
| Date |
March 9, 2006 |
|
Cassiopeia A - The Colorful
…
| Title |
Cassiopeia A - The Colorful Aftermath of a Violent Stellar Death |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. A new image taken with NASA's Hubble Space Telescope provides a detailed look at the tattered remains of a supernova explosion known as Cassiopeia A (Cas A). It is the youngest known remnant from a supernova explosion in the Milky Way. The new Hubble image shows the complex and intricate structure of the star's shattered fragments. The image is a composite made from 18 separate images taken in December 2004 using Hubble's Advanced Camera for Surveys (ACS). |
|
STEREO's Routes to Solar Orb
…
| Title |
STEREO's Routes to Solar Orbits |
| Abstract |
The two STEREO spacecraft, A (red path) and B (yellow path), are launched from the Earth into a highly eccentric orbit with an apogee that reaches the orbit of the Moon. Once in this orbit, the trajectories are adjusted so they can receive gravity-assists from the Moon. The gravity assist will send them both into heliocentric orbits, one spacecraft ahead of the Earth and the other behind the Earth. This trajectory was generated using a spacecraft ephemeris generated shortly after launch. |
| Completed |
2007-02-05 |
|
STEREO's Routes to Solar Orb
…
| Title |
STEREO's Routes to Solar Orbits |
| Abstract |
The two STEREO spacecraft, A (red path) and B (yellow path), are launched from the Earth into a highly eccentric orbit with an apogee that reaches the orbit of the Moon. Once in this orbit, the trajectories are adjusted so they can receive gravity-assists from the Moon. The gravity assist will send them both into heliocentric orbits, one spacecraft ahead of the Earth and the other behind the Earth. This trajectory was generated using a spacecraft ephemeris generated shortly after launch. |
| Completed |
2007-02-05 |
|
STEREO's Routes to Solar Orb
…
| Title |
STEREO's Routes to Solar Orbits |
| Abstract |
The two STEREO spacecraft, A (red path) and B (yellow path), are launched from the Earth into a highly eccentric orbit with an apogee that reaches the orbit of the Moon. Once in this orbit, the trajectories are adjusted so they can receive gravity-assists from the Moon. The gravity assist will send them both into heliocentric orbits, one spacecraft ahead of the Earth and the other behind the Earth. This trajectory was generated using a spacecraft ephemeris generated shortly after launch. |
| Completed |
2007-02-05 |
|
STEREO's Routes to Solar Orb
…
| Title |
STEREO's Routes to Solar Orbits |
| Abstract |
The two STEREO spacecraft, A (red path) and B (yellow path), are launched from the Earth into a highly eccentric orbit with an apogee that reaches the orbit of the Moon. Once in this orbit, the trajectories are adjusted so they can receive gravity-assists from the Moon. The gravity assist will send them both into heliocentric orbits, one spacecraft ahead of the Earth and the other behind the Earth. This trajectory was generated using a spacecraft ephemeris generated shortly after launch. |
| Completed |
2007-02-05 |
|
STEREO's Routes to Solar Orb
…
| Title |
STEREO's Routes to Solar Orbits |
| Abstract |
The two STEREO spacecraft, A (red path) and B (yellow path), are launched from the Earth into a highly eccentric orbit with an apogee that reaches the orbit of the Moon. Once in this orbit, the trajectories are adjusted so they can receive gravity-assists from the Moon. The gravity assist will send them both into heliocentric orbits, one spacecraft ahead of the Earth and the other behind the Earth. This trajectory was generated using a spacecraft ephemeris generated shortly after launch. |
| Completed |
2007-02-05 |
|
STEREO's Routes to Solar Orb
…
| Title |
STEREO's Routes to Solar Orbits |
| Abstract |
The two STEREO spacecraft, A (red path) and B (yellow path), are launched from the Earth into a highly eccentric orbit with an apogee that reaches the orbit of the Moon. Once in this orbit, the trajectories are adjusted so they can receive gravity-assists from the Moon. The gravity assist will send them both into heliocentric orbits, one spacecraft ahead of the Earth and the other behind the Earth. This trajectory was generated using a spacecraft ephemeris generated shortly after launch. |
| Completed |
2007-02-05 |
|
STEREO's Routes to Solar Orb
…
| Title |
STEREO's Routes to Solar Orbits |
| Abstract |
The two STEREO spacecraft, A (red path) and B (yellow path), are launched from the Earth into a highly eccentric orbit with an apogee that reaches the orbit of the Moon. Once in this orbit, the trajectories are adjusted so they can receive gravity-assists from the Moon. The gravity assist will send them both into heliocentric orbits, one spacecraft ahead of the Earth and the other behind the Earth. This trajectory was generated using a spacecraft ephemeris generated shortly after launch. |
| Completed |
2007-02-05 |
|
STEREO's Routes to Solar Orb
…
| Title |
STEREO's Routes to Solar Orbits |
| Abstract |
The two STEREO spacecraft, A (red path) and B (yellow path), are launched from the Earth into a highly eccentric orbit with an apogee that reaches the orbit of the Moon. Once in this orbit, the trajectories are adjusted so they can receive gravity-assists from the Moon. The gravity assist will send them both into heliocentric orbits, one spacecraft ahead of the Earth and the other behind the Earth. This trajectory was generated using a spacecraft ephemeris generated shortly after launch. |
| Completed |
2007-02-05 |
|
STEREO's Routes to Solar Orb
…
| Title |
STEREO's Routes to Solar Orbits |
| Abstract |
The two STEREO spacecraft, A (red path) and B (yellow path), are launched from the Earth into a highly eccentric orbit with an apogee that reaches the orbit of the Moon. Once in this orbit, the trajectories are adjusted so they can receive gravity-assists from the Moon. The gravity assist will send them both into heliocentric orbits, one spacecraft ahead of the Earth and the other behind the Earth. This trajectory was generated using a spacecraft ephemeris generated shortly after launch. |
| Completed |
2007-02-05 |
|
STEREO's Routes to Solar Orb
…
| Title |
STEREO's Routes to Solar Orbits |
| Abstract |
The two STEREO spacecraft, A (red path) and B (yellow path), are launched from the Earth into a highly eccentric orbit with an apogee that reaches the orbit of the Moon. Once in this orbit, the trajectories are adjusted so they can receive gravity-assists from the Moon. The gravity assist will send them both into heliocentric orbits, one spacecraft ahead of the Earth and the other behind the Earth. This trajectory was generated using a spacecraft ephemeris generated shortly after launch. |
| Completed |
2007-02-05 |
|
STEREO's Routes to Solar Orb
…
| Title |
STEREO's Routes to Solar Orbits |
| Abstract |
The two STEREO spacecraft, A (red path) and B (yellow path), are launched from the Earth into a highly eccentric orbit with an apogee that reaches the orbit of the Moon. Once in this orbit, the trajectories are adjusted so they can receive gravity-assists from the Moon. The gravity assist will send them both into heliocentric orbits, one spacecraft ahead of the Earth and the other behind the Earth. This trajectory was generated using a spacecraft ephemeris generated shortly after launch. |
| Completed |
2007-02-05 |
|
STEREO's Routes to Solar Orb
…
| Title |
STEREO's Routes to Solar Orbits |
| Abstract |
The two STEREO spacecraft, A (red path) and B (yellow path), are launched from the Earth into a highly eccentric orbit with an apogee that reaches the orbit of the Moon. Once in this orbit, the trajectories are adjusted so they can receive gravity-assists from the Moon. The gravity assist will send them both into heliocentric orbits, one spacecraft ahead of the Earth and the other behind the Earth. This trajectory was generated using a spacecraft ephemeris generated shortly after launch. |
| Completed |
2007-02-05 |
|
STEREO's Routes to Solar Orb
…
| Title |
STEREO's Routes to Solar Orbits |
| Abstract |
The two STEREO spacecraft, A (red path) and B (yellow path), are launched from the Earth into a highly eccentric orbit with an apogee that reaches the orbit of the Moon. Once in this orbit, the trajectories are adjusted so they can receive gravity-assists from the Moon. The gravity assist will send them both into heliocentric orbits, one spacecraft ahead of the Earth and the other behind the Earth. This trajectory was generated using a spacecraft ephemeris generated shortly after launch. |
| Completed |
2007-02-05 |
|
STEREO's Routes to Solar Orb
…
| Title |
STEREO's Routes to Solar Orbits |
| Abstract |
The two STEREO spacecraft, A (red path) and B (yellow path), are launched from the Earth into a highly eccentric orbit with an apogee that reaches the orbit of the Moon. Once in this orbit, the trajectories are adjusted so they can receive gravity-assists from the Moon. The gravity assist will send them both into heliocentric orbits, one spacecraft ahead of the Earth and the other behind the Earth. This trajectory was generated using a spacecraft ephemeris generated shortly after launch. |
| Completed |
2007-02-05 |
|
STEREO's Routes to Solar Orb
…
| Title |
STEREO's Routes to Solar Orbits |
| Abstract |
The two STEREO spacecraft, A (red path) and B (yellow path), are launched from the Earth into a highly eccentric orbit with an apogee that reaches the orbit of the Moon. Once in this orbit, the trajectories are adjusted so they can receive gravity-assists from the Moon. The gravity assist will send them both into heliocentric orbits, one spacecraft ahead of the Earth and the other behind the Earth. This trajectory was generated using a spacecraft ephemeris generated shortly after launch. |
| Completed |
2007-02-05 |
|
STEREO's Routes to Solar Orb
…
| Title |
STEREO's Routes to Solar Orbits |
| Abstract |
The two STEREO spacecraft, A (red path) and B (yellow path), are launched from the Earth into a highly eccentric orbit with an apogee that reaches the orbit of the Moon. Once in this orbit, the trajectories are adjusted so they can receive gravity-assists from the Moon. The gravity assist will send them both into heliocentric orbits, one spacecraft ahead of the Earth and the other behind the Earth. This trajectory was generated using a spacecraft ephemeris generated shortly after launch. |
| Completed |
2007-02-05 |
|
STEREO's Routes to Solar Orb
…
| Title |
STEREO's Routes to Solar Orbits |
| Abstract |
The two STEREO spacecraft, A (red path) and B (yellow path), are launched from the Earth into a highly eccentric orbit with an apogee that reaches the orbit of the Moon. Once in this orbit, the trajectories are adjusted so they can receive gravity-assists from the Moon. The gravity assist will send them both into heliocentric orbits, one spacecraft ahead of the Earth and the other behind the Earth. This trajectory was generated using a spacecraft ephemeris generated shortly after launch. |
| Completed |
2007-02-05 |
|
STEREO's Routes to Solar Orb
…
| Title |
STEREO's Routes to Solar Orbits |
| Abstract |
The two STEREO spacecraft, A (red path) and B (yellow path), are launched from the Earth into a highly eccentric orbit with an apogee that reaches the orbit of the Moon. Once in this orbit, the trajectories are adjusted so they can receive gravity-assists from the Moon. The gravity assist will send them both into heliocentric orbits, one spacecraft ahead of the Earth and the other behind the Earth. This trajectory was generated using a spacecraft ephemeris generated shortly after launch. |
| Completed |
2007-02-05 |
|
When Diamonds Aren't Forever
| Title |
When Diamonds Aren't Forever |
| Explanation |
The track of totality for the first solar eclipse of 2006 [ http://sunearth.gsfc.nasa.gov/eclipse/SEmono/TSE2006/ TSE2006.html ] began early yesterday on the east coast of Brazil and ended half a world away at sunset in western Mongolia [ http://antwrp.gsfc.nasa.gov/apod/ap020209.html ]. In between, the shadow [ http://antwrp.gsfc.nasa.gov/apod/ap040926.html ] of the Moon crossed the Atlantic Ocean, northern Africa, and central Asia, and so came for a moment to the small Greek island of Kastelorizo [ http://www.hri.org/infoxenios/english/dodecanese/kastelorizo/ history.html ] in the eastern Aegean. Astronomer Anthony Ayiomamitis reports that the islanders and many eclipse-watching [ http://www.spaceweather.com/eclipses/ gallery_29mar06.htm ] visitors were indeed treated to an inspiring display of the beautiful solar corona [ http://antwrp.gsfc.nasa.gov/apod/ap010408.html ] as totality lasted about three minutes. As the total phase [ http://www.mreclipse.com/Special/SEprimer.html ] of the eclipse ended, he was able to capture this striking "diamond ring" image [ http://www.perseus.gr/Astro-Eclipses-2006-03-29b.htm ]. In it, the first rays of sunlight shining through edge-on lunar valleys create the fleeting appearance of glistening diamonds set in a bright ring around the Moon's silhouette [ http://antwrp.gsfc.nasa.gov/apod/ap050506.html ]. |
|
Sharp Silhouette
| Title |
Sharp Silhouette |
| Explanation |
Though it's [ http://antwrp.gsfc.nasa.gov/apod/ap981212.html ] 93 million miles away, the Sun still hurts your eyes when you look at it. But bright sunlight (along with accurate planning and proper equipment!) resulted in this sharp silhouette [ http://www.astrophoto.fr/iss_atlantis_transit.html ] of spaceship and space station. The amazing telescopic view, recorded on September 17, captures shuttle orbiter Atlantis [ http://www.nasa.gov/centers/kennedy/shuttleoperations/ orbiters/atlantis-info.html ] and the International Space Station [ http://en.wikipedia.org/wiki/International_Space_Station ] in orbit over planet Earth. At a range of 550 kilometers from the observing site near Mamers, Normandy, France, Atlantis (left) has just undocked and moved about 200 meters away from the space station. Tomorrow, yet another [ http://antwrp.gsfc.nasa.gov/apod/ap050729.html ] satellite of planet Earth [ http://antwrp.gsfc.nasa.gov/apod/ap050430.html ] can be seen in silhouette - the Moon will eclipse the Sun. This last eclipse [ http://sunearth.gsfc.nasa.gov/eclipse/OH/ OH2006.html#2006Sep22A ] of 2006 will be seen as an annular [ http://antwrp.gsfc.nasa.gov/apod/ap051005.html ] solar eclipse along a track that crosses northern South America and the south Atlantic. |
|
Twenty Full Moons
| Title |
Twenty Full Moons |
| Explanation |
In celebration of tonight's Full Moon [ http://www.inconstantmoon.com/cyc_phas.htm ], the first of 2007, consider this grid of twenty Full Moons [ http://www.photoastronomique.net/ photo_us.php?nom=0505-0612 ]. From upper left to lower right, the images represent every lunation [ http://antwrp.gsfc.nasa.gov/apod/ap051113.html ] from May 2005 through December 2006. The consecutive Full Moons are all shown at the same scale [ http://antwrp.gsfc.nasa.gov/apod/ap061228.html ], so unlike the famous Moon Illusion [ http://antwrp.gsfc.nasa.gov/apod/ap031011.html ] the change in apparent size seen here is real. (For example, compare early and late 2006 Full Moons.) The change is caused by the variation [ http://www.fourmilab.ch/earthview/moon_ap_per.html ] in lunar distance due to the Moon's significantly non-circular orbit. A subtler change in appearance can also be noticed on close examination, as the Moon seems to wobble and rock slightly from one Full Moon to the next. This effect, known as libration [ http://www.phy6.org/stargaze/Smoon4.htm ], is more dramatic and easier to see in a twenty frame movie [ http://www.photoastronomique.net/geant/0505-0612.html ] comparing these twenty Full Moons. |
|
Sail On, Stardust
| Title |
Sail On, Stardust |
| Explanation |
Spacecraft on long interplanetary voyages [ http://www-spof.gsfc.nasa.gov/stargaze/Sintro.htm ] often use the planets themselves as gravitational "sling shots" to boost them along their way. Launched [ http://stardust.jpl.nasa.gov/news/ commemorative.html ] in February of 1999 on a historic voyage to a comet, the Stardust spacecraft [ http://stardust.jpl.nasa.gov/news/ega/ ] is no different. On 15 January 2001 Stardust made its closest approach to planet Earth [ http://stardust.jpl.nasa.gov/news/status/010115.html ] since launch, coming within about 6,000 kilometers of the surface. It used this gravity assist maneuver [ http://www.jpl.nasa.gov/basics/bsf4-1.htm#gravity ] to increase its speed and alter its trajectory toward an encounter with comet Wild 2 [ http://www.ssep.org/stardust/wild-2.html ], which it should reach in 2004. Shortly before its time of closest approach, astronomer Gordon Garradd recorded this exposure [ http://www.ozemail.com.au/~loomberah/stardust.htm ] of Stardust sailing through the skies above Loomberah, Australia. Nearby and moving fast [ http://stardust.jpl.nasa.gov/news/ega/images.html ], the spacecraft appears as a streak against a background of faint stars in the constellation Cetus [ http://www.astronomical.org/constellations/cet.html ]. Stardust cruised within just 98,000 kilometers of the Moon [ http://stardust.jpl.nasa.gov/news/ega/lunar.html ] about 15 hours later. After collecting [ http://stardust.jpl.nasa.gov/tech/ aerogel.html ] dust from the tail of comet Wild 2, Stardust's voyage [ http://stardust.jpl.nasa.gov/mission/details.html ] will continue -- as it returns the samples to Earth in 2006. |
|
A Blue Crescent Moon from Sp
…
| Title |
A Blue Crescent Moon from Space |
| Explanation |
What's happening to the Moon? Drifting around the Earth in 2006 July, astronauts from the International Space Station [ http://antwrp.gsfc.nasa.gov/apod/ap060920.html ] (ISS) captured a crescent Moon [ http://antwrp.gsfc.nasa.gov/apod/ap060618.html ] floating far beyond the horizon. The captured above image [ http://eobadmin.gsfc.nasa.gov/Newsroom/NewImages/images.php3?img_id=17542 ] is interesting because part of the Moon appears blue [ http://antwrp.gsfc.nasa.gov/apod/ap040731.html ], and because part of the moon appears missing. Both effects are created by the Earth's atmosphere [ http://csep10.phys.utk.edu/astr161/lect/earth/atmosphere.html ]. Air molecules [ http://en.wikipedia.org/wiki/Molecules ] more efficiently scatter increasingly blue light, making the clear day sky blue [ http://math.ucr.edu/home/baez/physics/General/BlueSky/blue_sky.html ] for ground observers, and the horizon blue for astronauts. Besides reflecting sunlight, these atmospheric molecules [ http://en.wikipedia.org/wiki/Air ] also deflect moonlight, making the lower part of the moon appear to fade away. As one looks higher in the photograph [ http://eol.jsc.nasa.gov/scripts/sseop/photo.pl?mission=ISS013&roll=E&frame=54329 ], the increasingly thin atmosphere appears to fade to black [ http://antwrp.gsfc.nasa.gov/apod/ap000913.html ]. |
|
3D Full Moon
| Title |
3D Full Moon |
| Explanation |
Get out your red/blue glasses [ http://photojournal.jpl.nasa.gov/Help/ VendorList.html#Glasses ] and check out this satisfying stereo anaglyph [ http://faxmentis.org/html/ana-howto.html ] of the Full Moon. A corresponding stereo image pair, intended for cross-eyed viewing [ http://www.3dexpo.com/crosseye.htm ], is also available through this link [ http://www.pixheaven.net/ photo_us.php?nom=0505-0704_0611-0701x ]. Regardless of your preferred technique for stereo viewing [ http://photojournal.jpl.nasa.gov/feature/anaglyph ], the 3D effect comes from combining pictures of the same scene taken at different angles -- mimicking the slightly different perspective of each eye. Perhaps surprisingly for Earthdwellers [ http://commons.wikimedia.org/wiki/ Image:Georges_Seurat_-_Un_dimanche_apr%C3%A8s-midi_%C3%A0_l%27%C3%8Ele_de_la_Grande_Jatte.jpg ], getting two pictures of the Full Moon from different angles only requires a little patience. In this case, photographer Laurent Laveder used pictures taken months apart, one in November 2006 and one in January 2007. He relied on the Moon's continuous libration [ http://www.phy6.org/stargaze/Smoon4.htm ] or wobble as it orbits to produce two shifted images of a Full Moon [ http://antwrp.gsfc.nasa.gov/apod/ap070103.html ]. |
|
1006 AD: Supernova in the Sk
…
| Title |
1006 AD: Supernova in the Sky |
| Explanation |
A new star, likely the brightest supernova [ http://antwrp.gsfc.nasa.gov/apod/ap030317.html ] in recorded human history [ http://www.seds.org/messier/more/mw_sn.html ], appeared in planet Earth's sky in the year 1006 AD. The expanding debris cloud [ http://antwrp.gsfc.nasa.gov/apod/ap001202.html ] from the stellar explosion is still visible to modern astronomers, but what did the supernova look like in 1006? Astronomer Tunç Tezel offers this suggestion, based on a photograph he took on February 22, 1998 from a site overlooking the Mediterranean [ http://antwrp.gsfc.nasa.gov/apod/ap011207.html ] south of Antalya, Turkey. On that date, bright Venus and a waning crescent Moon shone in [ http://antwrp.gsfc.nasa.gov/apod/ap020619.html ] the early morning sky. Adopting recent calculations [ http://www.noao.edu/outreach/press/pr03/pr0304.html ] which put the supernova's apparent brightness between Venus and the crescent Moon, he digitally superposed an appropriate new star in the picture. He placed the star at the supernova's position in the southerly constellation of Lupus [ http://www.seasky.org/pictures/ sky7b06.html#Lupus ] and used the water's reflection of moonlight [ http://antwrp.gsfc.nasa.gov/apod/ap021122.html ] in the final image. Tezel hopes to view the total solar eclipse of 29 March 2006 [ http://newton.physics.metu.edu.tr/~aat/TSE2006/TSE2006.html ] from this same site -- on the 1,000th anniversary of Supernova 1006 [ http://www.seds.org/~spider/spider/Misc/sn1006.html ]. |
|
Clouds, Plane, Sun, Eclipse
| Title |
Clouds, Plane, Sun, Eclipse |
| Explanation |
How can part of the Sun just disappear? When that part is really hiding behind the Moon [ http://antwrp.gsfc.nasa.gov/apod/ap050407.html ]. Last Friday, the first partial solar eclipse [ http://csep10.phys.utk.edu/astr161/lect/time/eclipses.html ] of 2005 and the last total eclipse [ http://sunearth.gsfc.nasa.gov/eclipse/eclipse.html ] of the Sun until March 2006 was visible. During a solar eclipse [ http://en.wikipedia.org/wiki/Solar_eclipse ], the Sun [ http://www.nineplanets.org/sol.html ], Moon [ http://antwrp.gsfc.nasa.gov/apod/ap031011.html ] and Earth are aligned. The total solar eclipse [ http://antwrp.gsfc.nasa.gov/apod/ap010408.html ] was primarily visible from the Southern Pacific Ocean [ http://www.cia.gov/cia/publications/factbook/geos/zn.html ], while a partial solar eclipse [ http://antwrp.gsfc.nasa.gov/apod/ap040926.html ] was discoverable across South America [ http://en.wikipedia.org/wiki/South_America ] and lower North America [ http://en.wikipedia.org/wiki/North_America ]. The above image composite was taken with a handheld digital camera last Friday. After a day of rain in Mt. Holly, North Carolina [ http://en.wikipedia.org/wiki/North_Carolina ], USA [ http://www.cia.gov/cia/publications/factbook/geos/us.html ], a partially eclipsed Sun momentarily peeked through a cloudy sky [ http://antwrp.gsfc.nasa.gov/apod/ap030618.html ]. After taking a sequence of images, the best eclipse shot [ http://spaceweather.com/eclipses/gallery_08apr05.html ] was digitally combined with a less good eclipse shot that featured a passing airplane [ http://antwrp.gsfc.nasa.gov/apod/ap010129.html ]. |
|
Titan's Odd Spot
| Title |
Titan's Odd Spot |
| Explanation |
Titan's odd spot [ http://www.jpl.nasa.gov/news/ news.cfm?release=2005-086 ] could be a cloud, but if so, it's a persistent one. Peering into the thick, hazy atmosphere [ http://antwrp.gsfc.nasa.gov/apod/ap041028.html ] of Saturn's largest moon [ http://www.nineplanets.org/titan.html ], cameras on board the Cassini spacecraft found a bright spot [ http://photojournal.jpl.nasa.gov/catalog/PIA07876 ] at the same location during Titan encounters in 2005 and 2004. Seen near Titan's upper edge in this false-color image [ http://photojournal.jpl.nasa.gov/catalog/PIA07877 ] from the VIMS instrument [ http://wwwvims.lpl.arizona.edu/more_new.htm ], the spot is almost 500 kilometers wide, and is brightest at infrared wavelengths. In addition to suggesting the uniquely colored spot is a persistent cloud possibly controlled by surface features, researchers also entertain the idea that the spot is caused by unusual surface material or extremely tall mountains. They also note the bright infrared [ http://coolcosmos.ipac.caltech.edu/ ] spot could be hot. Further clues to the odd spot's nature will come during a planned encounter [ http://saturn.jpl.nasa.gov/operations/ saturn-tour-dates-06.cfm ] in July 2006 when Cassini's cameras will look at the spot during Titan's night [ http://photojournal.jpl.nasa.gov/catalog/PIA06184 ]. If it glows at night, it's hot [ http://antwrp.gsfc.nasa.gov/apod/ap050423.html ]. |
|
Searching for Warmth
PIA07794
Saturn
Composite Infrared Spectrome
…
| Title |
Searching for Warmth |
| Original Caption Released with Image |
. The imaging team homepage is at http://ciclops.org [ http://ciclops.org ], The exciting mystery of an active south polar region on Saturn's icy moon Enceladus continues to unfold as scientists make the correlation between geologically youthful surface fractures and unusually warm temperatures. This view shows excess heat radiation from cracks near the moon's south pole. These warm fissures are the source of plumes of dust and gas seen by multiple instruments on the Cassini spacecraft during its flyby of Enceladus on July 14, 2005, as described in a series of papers in the March 10, 2006, issue of the journal Science. This image shows two arrays of temperature readings across the surface of Enceladus, as measured by the Cassini composite infrared spectrometer, superimposed on images of the surface taken simultaneously by the imaging science subsystem. Surface temperatures in Kelvin, derived from the intensity of infrared radiation detected by composite infrared spectrometer, are shown along with their formal uncertainties, although true uncertainties for temperatures below about 75 Kelvin (minus 325 degrees Fahrenheit) are not easily described by a single number. Enhanced thermal emission is seen in the vicinity of the prominent "tiger stripe" fissures discovered by the imaging cameras. In this image, the excess emission is near the center of the composite infrared spectrometer array, directly over a tiger stripe fissure. The peak temperatures, 86 Kelvin and 90 Kelvin (minus 305 and minus 298 degrees Fahrenheit) respectively, are averages over the composite infrared spectrometer field of view, and other composite and infrared spectrometer data suggest that much higher temperatures, up to at least 145 Kelvin (minus 199 degrees Fahrenheit), occur in narrow zones a few hundred meters wide along the tiger stripe fissures. See PIA07793 [ http://photojournal.jpl.nasa.gov/catalog/PIA07793 ] for a related image. This image was taken nearly three times closer to the moon and is centered near longitude 120 west, latitude 82 south, and each composite infrared spectrometer field of view is 6.0 kilometers (3.7 miles) across. This Cassini narrow-angle camera image was cropped and resized for presentation. 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 was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. 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 [ http://saturn.jpl.nasa.gov ]. The composite infrared spectrometer team homepage is http://cirs.gsfc.nasa.gov/ [ http://cirs.gsfc.nasa.gov/ ] |
|
Searching for Warmth
PIA07793
Saturn
Composite Infrared Spectrome
…
| Title |
Searching for Warmth |
| Original Caption Released with Image |
http://cirs.gsfc.nasa.gov/ [ http://cirs.gsfc.nasa.gov/ ]. The imaging team homepage is at http://ciclops.org [ http://ciclops.org ], The exciting mystery of an active south polar region on Saturn's icy moon Enceladus continues to unfold as scientists make the correlation between geologically youthful surface fractures and unusually warm temperatures. This view shows excess heat radiation from cracks near the moon's south pole. These warm fissures are the source of plumes of dust and gas seen by multiple instruments on the Cassini spacecraft during its flyby of Enceladus on July 14, 2005, as described in a series of papers in the March 10, 2006, issue of the journal Science. This image shows two arrays of temperature readings across the surface of Enceladus, as measured by the Cassini composite infrared spectrometer, superimposed on images of the surface taken simultaneously by the imaging science subsystem. Surface temperatures in Kelvin, derived from the intensity of infrared radiation detected by the composite infrared spectrometer, are shown along with their formal uncertainties, although true uncertainties for temperatures below about 75 Kelvin (minus 325 degrees Fahrenheit) are not easily described by a single number. Enhanced thermal emission is seen in the vicinity of the prominent "tiger stripe" fissures discovered by the imaging cameras. In this image, the excess emission is most strongly seen in the left-most composite infrared spectrometer field of view, which includes a fissure near the end of one of the tiger stripes. The peak temperatures, 86 Kelvin and 90 Kelvin (minus 305 and minus 298 degrees Fahrenheit) respectively, are averages over the composite infrared spectrometer field of view, and other composite infrared spectrometer data suggest that much higher temperatures, up to at least 145 Kelvin (minus 199 degrees Fahrenheit), occur in narrow zones a few hundred meters wide along the tiger stripe fissures. See PIA07794 [ http://photojournal.jpl.nasa.gov/catalog/PIA07794 ] for a related image. This image is centered near longitude 135 west, latitude 65 south, and each square from the composite infrared spectrometer field of view is 17.5 kilometers (10.9 miles) across. This Cassini narrow-angle camera image has been cropped and resized for presentation. 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 was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. 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 [ http://saturn.jpl.nasa.gov ]. The composite infrared spectrometer team homepage is |
|
Enceladus Keeps the Home Fir
…
PIA09037
Saturn
Composite Infrared Spectrome
…
| Title |
Enceladus Keeps the Home Fires Burning |
| Original Caption Released with Image |
On Nov. 9, 2006, Cassini's composite infrared spectrometer captured its first view of the infrared heat radiation emanating from the "tiger stripe" fractures at the south pole of Saturn's moon Enceladus (right) since the discovery of the hot spot 16 months earlier (left). The original discovery was made just before a close flyby of Enceladus on July 14, 2005, and coincided with the discovery of plumes of water-rich gas and ice particles jetting out of the tiger stripes. However, the spacecraft's orbit did not provide any good views of the south pole for follow-up observations until November 2006. The new observations were made from a range of 110,000 kilometers (68,350 miles), slightly more distant than the 80,000-kilometer range (49,700 miles) of the original observations. Comparison of the two images shows that the south polar region continues to be active, and the distribution of temperatures there has changed little in 16 months. The distribution of heat radiation suggests that most or all of the south polar heat comes from the tiger stripes themselves, though the individual stripes are not resolved at the approximate 30-kilometer (19-mile) spatial resolution of these images. The images show the intensity of heat radiation in the 10- to 16-micron wavelength range, translated into temperature and displayed in false color. Peak south polar temperature on both dates reached about 85 Kelvin (minus 306 degrees Fahrenheit), averaged over the 30-kilometer (19-mile) spatial resolution of the data. However, the variation in brightness with wavelength, which is also measured by the composite infrared spectrometer, reveals that the warm region includes small areas, possibly zones a few 100 meters (320 feet) wide along the length of the tiger stripes, that are at higher temperatures, reaching at least 130 Kelvin (minus 225 degrees Fahrenheit) and perhaps much warmer still. While the south polar tiger stripes are almost certainly heated by energy from the moon's interior, daytime regions at low latitudes are warmed by sunlight to temperatures in the high 70s Kelvin (about minus 320 degrees Fahrenheit). The white numbers on the images show west longitudes on Enceladus, which is 500 kilometers (310 miles) in diameter. The dashed line shows the terminator, the boundary between day and night. The blotchy appearance of the cooler regions away from the south pole, and of the sky beyond the globe of Enceladus, is an artifact resulting from the fact that apart from the polar hot spot, the composite infrared spectrometer can barely detect the very faint heat radiation from this very cold moon. 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 was designed, developed and assembled at JPL. The, composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/ [ http://saturn.jpl.nasa.gov ]. The composite infrared spectrometer team homepage is http://cirs.gsfc.nasa.gov/ [ http://cirs.gsfc.nasa.gov/ ]. |
|
|
