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First Steps for Lunar Impact …
The Mission Objectives of th …
3/27/08
Title First Steps for Lunar Impactor
Date 3/27/08
Description The Mission Objectives of the Lunar Crater Observation and Sensing Satellite (LCROSS) include confirming the presence or absence of water ice in a permanently shadowed crater at the Moonï˜∑__s South Pole.
A Twisted Tale
Description A Twisted Tale
Full Description Saturn's D ring--the innermost of the planet's rings--sports an intriguing structure that appears to be a wavy, or "vertically corrugated," spiral. This continuously changing ring structure provides circumstantial evidence for a possible recent collision event in the rings. Support for this idea comes from the appearance of a structure in the outer D-ring that looks, upon close examination, like a series of bright ringlets with a regularly spaced interval of about 30 kilometers (19 miles). When viewed along a line of sight nearly in the ringplane, a pattern of brightness reversals is observed: a part of the ring that appears bright on the far side of the rings appears dark on the near side of the rings, and vice versa (see D Ring Sight Lines). This phenomenon would occur if the region contains a sheet of fine material that is vertically corrugated, like a tin roof. In this case, variations in brightness would correspond to changing slopes in the rippled ring material (see image with inset graphic). An observation made with NASA's Hubble Space Telescope in 1995 also saw a periodic structure in the outer D ring, but its wavelength was then 60 kilometers (37 miles). There were insufficient observations to discern the spiral nature of the feature. Thus, it appears the wavelength of the wavy structure has been decreasing: that is, this feature has been winding up like a spring over time. The rate at which the pattern appears to be winding up is quite close to the rate scientists would expect for a vertically corrugated spiraling sheet of material at this location in the rings that is responding to gravitational forcing from Saturn. As Cassini imaging scientists extrapolated the spiraling trend backward in time, they found that it completely unwound in 1984, leaving only an inclined, or tilted, sheet of material. The researchers speculate such an inclined sheet may have been produced around that time by the impact of a comet or meteoroid into the D ring which kicked out a cloud of fine particles that ultimately inherited some of the tilt of the impactor's trajectory as it slammed into the rings. Another possibility is that the impactor struck an already inclined moonlet, shattered it to bits and the debris remained in an inclined orbit. 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 11, 2006
A Twisted Tale (with inset g …
Description A Twisted Tale (with inset graphic)
Full Description Saturn's D ring--the innermost of the planet's rings--sports an intriguing structure that appears to be a wavy, or "vertically corrugated," spiral. This continuously changing ring structure provides circumstantial evidence for a possible recent collision event in the rings. Support for this idea comes from the appearance of a structure in the outer D-ring that looks, upon close examination, like a series of bright ringlets with a regularly spaced interval of about 30 kilometers (19 miles). When viewed along a line of sight nearly in the ringplane, a pattern of brightness reversals is observed: a part of the ring that appears bright on the far side of the rings appears dark on the near side of the rings, and vice versa (see D Ring Sight Lines). This phenomenon would occur if the region contains a sheet of fine material that is vertically corrugated, like a tin roof. In this case, variations in brightness would correspond to changing slopes in the rippled ring material. An observation made with NASA's Hubble Space Telescope in 1995 also saw a periodic structure in the outer D ring, but its wavelength was then 60 kilometers (37 miles). There were insufficient observations to discern the spiral nature of the feature. Thus, it appears the wavelength of the wavy structure has been decreasing: that is, this feature has been winding up like a spring over time. The rate at which the pattern appears to be winding up is quite close to the rate scientists would expect for a vertically corrugated spiraling sheet of material at this location in the rings that is responding to gravitational forcing from Saturn. As Cassini imaging scientists extrapolated the spiraling trend backward in time, they found that it completely unwound in 1984, leaving only an inclined, or tilted, sheet of material. The researchers speculate such an inclined sheet may have been produced around that time by the impact of a comet or meteoroid into the D ring which kicked out a cloud of fine particles that ultimately inherited some of the tilt of the impactor's trajectory as it slammed into the rings. Another possibility is that the impactor struck an already inclined moonlet, shattered it to bits and the debris remained in an inclined orbit. 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 11, 2006
Tethys and Titan
Description Cassini looks toward Tethys and its great crater Odysseus, while at the same time capturing veiled Titan in the distance (at left).
Full Description Cassini looks toward Tethys and its great crater Odysseus, while at the same time capturing veiled Titan in the distance (at left). Titan (5,150 kilometers, or 3,200 miles across) is shrouded in a thick, smog-like atmosphere in which many small, potential impactors burn up before hitting the moon's surface. Crater-pocked Tethys (1,071 kilometers, or 665 miles across) has no such protective layer, although even a thick blanket of atmosphere would have done little good against the impactor that created Odysseus. The eastern limb of Tethys is overexposed in this view. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Jan. 6, 2006, at a distance of approximately 4 million kilometers (2.5 million miles) from Titan and 2.7 million kilometers (1.7 million miles) from Tethys. The image scale is 25 kilometers (16 miles) per pixel on Titan and 16 kilometers (10 miles) per pixel on Tethys. 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 February 17, 2006
Deep Impact Launch
title Deep Impact Launch
date 01.12.2005
description Erupting from the flames and smoke beneath it, NASA's Deep Impact spacecraft lifts off at 1:47 p.m. EST today from Launch Pad 17-B, Cape Canaveral Air Force Station, Fla. A NASA Discovery mission, Deep Impact is heading for space and a rendezvous 83 million miles from Earth with Comet Tempel 1. After releasing a 3- by 3-foot projectile (impactor) to crash onto the surface July 4, 2005, Deep Impact's flyby spacecraft will reveal the secrets of the comet's interior by collecting pictures and data of how the crater forms, measuring the crater's depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. *Image Credit*: NASA
Deep Impact
title Deep Impact
description This is an artist's rendition of the flyby spacecraft releasing the impactor, 24 hours before the impact event. Pictured from left to right are comet Tempel 1, the impactor, and the flyby spacecraft. The impactor is a 370-kilogram mass with an onboard guidance system. The flyby spacecraft includes a solar panel (right), a high-gain antenna (top), a debris shield (left, background), and science instruments for high and medium resolution imaging, infrared spectroscopy, and optical navigation (yellow box and cylinder, lower left). The fly spacecraft is about 3.2 meters long, 1.7 meters wide, and 2.3 meters high. The launch payload has a mass of 1020 kilograms. *Image Credit*: NASA
Ganymede's Khensu Crater
title Ganymede's Khensu Crater
date 09.06.1996
description The dark-floored crater Khensu is the target of this image of Ganymede. The Solid-State Imaging System onboard the Galileo spacecraft imaged this region as it passed Ganymede during its second orbit through the jovian system. Khensu is located at 20N latitude and 1530W longitude in a region of bright terrain known as Uruk Sulcus, and is about 13 kilometers in diameter. Like some other craters on Ganymede, it possesses an unusually dark floor and a bright ejecta blanket. The dark component may be residual material from the impactor that formed the crater. Another possibility is that the impactor may have punched through the bright surface to reveal a dark layer beneath. Another large crater named El is partly visible in the top righthand corner of the image. This crater is 54 kilometers in diameter and has a small "pit" in its center. Craters with such a "central pit" are common across Ganymede and are especially intriguing since they may reveal secrets about the structure of the satellite's shallow subsurface. North is to the upper left of the picture, and the Sun illuminates the surface from nearly overhead. The image covers an area about 100 by 86 kilometers across at a resolution of 111 meters per picture element. The image was taken on September 6, 1996, by the Solid-State Imaging System onboard the Galileo spacecraft. *Image Credit*: Brown University
Comet Tempel 1 Animations
Name Comet Tempel 1 Animations
Hubble Ultraviolet Image of …
Title Hubble Ultraviolet Image of Multiple Comet Impacts on Jupiter
Araona Crater (Iturralde Str …
Title Araona Crater (Iturralde Structure) With Labels
Abstract The Araona Crater (also known as the Iturralde Structure) is a suspected crater from an impactor which struck northern Bolivia approximately 20,000 years ago. The feature is believed to have been caused by a short period comet striking at 70 kilometres per second and splattering into the muddy alluvial flood plain in the Lower Amazon jungle. The impact created a circular depression which is now roughly 8 kilometres across and 3 metres deep. The structure was discovered in 1988 Landsat data, but was not visited successfully until 1998 because the region is inaccessible. Future expeditions hope to finally settle if the feature truly is the impact crater it appears to be, and if so, determine the nature of the impactor. The full Landsat scene of Northern Bolivia includes the Rio Bene running northward through the image (North is up), with the Rio Madidi running across the image from southwest towards the northeast before joining the Rio Bene. The image was constructed from Landsat Thematic Mapper bands 7, 5, and 3 displayed as red, green, and blue respectively. The green tone of the image distinguishes between different types of vegetation with low scrubland in the alluvial flood plain appears as a light green and dense tropical jungle coverage appearing dark green. The close-up of the impact crater uses the same Landsat data, but passed through a sharpening image filter which emphasizes high spatial frequency features and tends to enhance color contrast.
Completed 1999-04-09
Araona Crater (Iturralde Str …
Title Araona Crater (Iturralde Structure) With Labels
Abstract The Araona Crater (also known as the Iturralde Structure) is a suspected crater from an impactor which struck northern Bolivia approximately 20,000 years ago. The feature is believed to have been caused by a short period comet striking at 70 kilometres per second and splattering into the muddy alluvial flood plain in the Lower Amazon jungle. The impact created a circular depression which is now roughly 8 kilometres across and 3 metres deep. The structure was discovered in 1988 Landsat data, but was not visited successfully until 1998 because the region is inaccessible. Future expeditions hope to finally settle if the feature truly is the impact crater it appears to be, and if so, determine the nature of the impactor. The full Landsat scene of Northern Bolivia includes the Rio Bene running northward through the image (North is up), with the Rio Madidi running across the image from southwest towards the northeast before joining the Rio Bene. The image was constructed from Landsat Thematic Mapper bands 7, 5, and 3 displayed as red, green, and blue respectively. The green tone of the image distinguishes between different types of vegetation with low scrubland in the alluvial flood plain appears as a light green and dense tropical jungle coverage appearing dark green. The close-up of the impact crater uses the same Landsat data, but passed through a sharpening image filter which emphasizes high spatial frequency features and tends to enhance color contrast.
Completed 1999-04-09
Araona Crater (Iturralde Str …
Title Araona Crater (Iturralde Structure) With Labels
Abstract The Araona Crater (also known as the Iturralde Structure) is a suspected crater from an impactor which struck northern Bolivia approximately 20,000 years ago. The feature is believed to have been caused by a short period comet striking at 70 kilometres per second and splattering into the muddy alluvial flood plain in the Lower Amazon jungle. The impact created a circular depression which is now roughly 8 kilometres across and 3 metres deep. The structure was discovered in 1988 Landsat data, but was not visited successfully until 1998 because the region is inaccessible. Future expeditions hope to finally settle if the feature truly is the impact crater it appears to be, and if so, determine the nature of the impactor. The full Landsat scene of Northern Bolivia includes the Rio Bene running northward through the image (North is up), with the Rio Madidi running across the image from southwest towards the northeast before joining the Rio Bene. The image was constructed from Landsat Thematic Mapper bands 7, 5, and 3 displayed as red, green, and blue respectively. The green tone of the image distinguishes between different types of vegetation with low scrubland in the alluvial flood plain appears as a light green and dense tropical jungle coverage appearing dark green. The close-up of the impact crater uses the same Landsat data, but passed through a sharpening image filter which emphasizes high spatial frequency features and tends to enhance color contrast.
Completed 1999-04-09
Deep Impact Spacecraft Colli …
Name of Image Deep Impact Spacecraft Collides With Comet Tempel 1 (Video)
Date of Image 2005-07-04
Full Description After 172 days and 268 million miles of deep space travel, the NASA Deep Impact spacecraft successfully reached out and touched comet Tempel 1. The collision between the coffee table-sized space probe and city-sized comet occurred July 4, 2005 at 12:52 a.m. CDT. Comprised of images taken by the targeting sensor aboard the impactor probe, this movie shows the spacecraft approaching the comet up to just seconds before impact. Mission scientists expect Deep Impact to provide answers to basic questions about the formation of the solar system. Principal investigator for Deep Impact, Dr. Michael A?Hearn of the University of Maryland in College Park, is responsible for the mission, and project management is handled by the Jet Propulsion Laboratory in Pasadena, California. The program office at the Marshall Space Flight Center (MSFC) in Huntsville, Alabama assisted the Science Mission Directorate at NASA Headquarters in Washington with program management, technology planning, systems assessment, flight assurance and public outreach. The spacecraft was built for NASA by Ball Aerospace & Technologies Corporation of Boulder, Colorado. (NASA/JPL-Caltech/UMD)
Artist rendering of dust gra …
Name of Image Artist rendering of dust grains colliding at low speeds
Date of Image 2003-01-22
Full Description Clues to the formation of planets and planetary rings -- like Saturn's dazzling ring system -- may be found by studying how dust grains interact as they collide at low speeds. To study the question of low-speed dust collisions, NASA sponsored the COLLisions Into Dust Experiment (COLLIDE) at the University of Colorado. It was designed to spring-launch marble-size projectiles into trays of powder similar to space or lunar dust. COLLIDE-1 (1998) discovered that collisions below a certain energy threshold eject no material. COLLIDE-2 was designed to identify where the threshold is. In COLLIDE-2, scientists nudged small projectiles into dust beds and recorded how the dust splashed outward (video frame at top, artist's rendering at bottom). The slowest impactor ejected no material and stuck in the target. The faster impactors produced ejecta, some rebounded while others stuck in the target.
3D Barringer Meteorite Crate …
Title 3D Barringer Meteorite Crater
Explanation Barringer Meteorite Crater [ http://en.wikipedia.org/wiki/Meteor_Crater ], near Winslow, Arizona, is one of the best known impact craters on planet Earth [ http://www.unb.ca/passc/ImpactDatabase/images/ barringer.htm ]. View this color stereo anaglyph [ http://www.photomeeting.de/astromeeting/miscellaneous/ 070616crater3D_d.htm ] with red/blue glasses [ http://photojournal.jpl.nasa.gov/Help/ VendorList.html#Glasses ] to get a dramatic sense of the crater's [ http://barringercrater.com/ ] dimensions -- one mile wide, and up to 570 feet deep. (A cross-eyed stereo pair is available here [ http://www.astromeeting.de/miscellaneous/ 070616crater_x.htm ].) Historically, this crater is the first recognized to be caused by an impact rather than a volcanic eruption. Modern research [ http://www.astrobio.net/news/article1479.html ] indicates that the impactor responsible, a 300,000 ton nickel-iron meteor [ http://www.seds.org/nineplanets/nineplanets/ meteorites.html ], struck some 50,000 years ago. Estimates suggest that it was about 130 feet across and was traveling over 26,000 miles per hour. For comparison, the asteroid or comet impactor that created the Chicxulub crater [ http://antwrp.gsfc.nasa.gov/apod/ap000226.html ] 65 million years ago, and is thought to have caused the extinction of the dinosaurs, was 6 to 12 miles across.
Deep Impact Spacecraft Hurtl …
Title Deep Impact Spacecraft Hurtles Toward Comet
Explanation What happens when you crash into a comet? That was a question considered by astronomers [ http://deepimpact.jpl.nasa.gov/mission/bios.html ] when they designed the Deep Impact mission [ http://deepimpact.jpl.nasa.gov/index.html ], launched in January. This coming July 4, the Deep Impact spaceship will reach its target - Comet Tempel 1 [ http://antwrp.gsfc.nasa.gov/apod/ap050512.html ] -- and release an impactor over five times the mass of a person toward its surface. The mothership will photograph the result. The remaining crater [ http://www.planetary.org/deepimpact/di_crater.html ] may tell how Tempel 1 is constructed. If, for example, Comet Tempel 1 [ http://deepimpact.jpl.nasa.gov/science/tempel1.html ] is an extremely loose pile of debris, the impactor may leave little or no discernable crater. On the other hand, if the comet's surface is relatively firm, the impactor's ripple may leave quite a large crater. A contest is even being held [ http://www.planetary.org/deepimpact/contest_enter.html ] to predict the size of the resulting crater. Pictured above [ http://www.planetary.org/deepimpact/di.html ] is an artist's impression of the initial encounter between the spacecraft and the comet.
Thirteen Million Kilometers …
Title Thirteen Million Kilometers from Comet Tempel 1
Explanation The Deep Impact spacecraft continues to close on Comet Tempel 1, a comet roughly the size of Manhattan. Early on July 3 (EDT), the Deep Impact [ http://deepimpact.jpl.nasa.gov/home/index.html ] spacecraft will separate [ http://www.space.com/businesstechnology/technology/050615_deepimpact_tech.html ] in to two individual robotic spaceships, one called Flyby and the other called Impactor. During the next 24 hours, both Flyby and Impactor will fire rockets and undergo complex maneuvers in preparation for Impactor's planned collision [ http://antwrp.gsfc.nasa.gov/apod/ap050516.html ] with Comet Tempel 1 [ http://deepimpact.jpl.nasa.gov/science/tempel1.html ]. On July 4 (1:52 am EDT) if everything goes as scheduled, the 370-kilogram Impactor will strike Tempel 1 [ http://cometography.com/pcomets/009p.html ]'s surface at over 14,000 kilometers per hour. Impactor will attempt to photograph the oncoming comet right up to the time of collision, while Flyby photographs the result from nearby. The above image [ http://deepimpact.jpl.nasa.gov/gallery/DI_T1_doy171.html ] was taken on 19 June from about 13 million kilometers out and used to help identify the central nucleus [ http://deepimpact.jpl.nasa.gov/press/050621umd.html ] of the comet inside the diffuse coma [ http://www.windows.ucar.edu/tour/link=/comets/coma.html ]. Telescopes around the Earth, including the Hubble Space Telescope, will also be closely watching [ http://hubblesite.org/newscenter/newsdesk/ archive/releases/2005/16/ ] the distant silent space ballet [ http://www.ebertfest.com/three/32001.htm ]. The result may give crucial information about the structure of comets [ http://antwrp.gsfc.nasa.gov/apod/ap040319.html ] and the early history of our Solar System [ http://www.bbc.co.uk/science/space/origins/building/index.shtml ].
Thirteen Seconds After Impac …
Title Thirteen Seconds After Impact
Explanation Fireworks came early on July 4th [ http://lcweb2.loc.gov/ammem/today/jul04.html ] when, at 1:52am EDT, the Deep Impact [ http://deepimpact.jpl.nasa.gov/home/index.html ] spacecraft's probe smashed into the surface of Comet Tempel 1's nucleus at ten kilometers per "second". The well-targeted impactor probe was vaporized as it blasted out an expanding cloud of material, seen here 13 seconds [ http://photojournal.jpl.nasa.gov/catalog/PIA02123 ] after the collision. The image is part of a stunning series [ http://photojournal.jpl.nasa.gov/catalog/PIA02125 ] of frames documenting the event from the high resolution camera onboard the flyby spacecraft [ http://deepimpact.jpl.nasa.gov/tech/flyby.html ]. Tempel 1's potato-shaped nucleus is approximately 5 kilometers across as seen from this perspective. Cameras onboard the impactor probe [ http://deepimpact.jpl.nasa.gov/tech/impactor.html ] were also able to image the nucleus and impact site up-close ... until about 3 seconds before the impact. Of course, telescopes nearer to planet Earth followed the event [ http://hubblesite.org/newscenter/newsdesk/archive/ releases/2005/17/ ], detecting a significant brightening of comet Tempel 1 [ http://antwrp.gsfc.nasa.gov/apod/ap050512.html ].
The Landscape on Comet Tempe …
Title The Landscape on Comet Tempel 1
Explanation This diverse landscape is the surface of comet Temple 1's [ http://antwrp.gsfc.nasa.gov/apod/ap050512.html ] nucleus as seen by the Deep Impact probe's Impactor Targeting Sensor [ http://deepimpact.jpl.nasa.gov/tech/impactor.html ]. Within minutes of recording the rugged view [ http://photojournal.jpl.nasa.gov/catalog/PIA02135 ], the landscape had changed dramatically though, as the impactor smashed into the surface near the two large, half kilometer-sized craters at picture center. Indications [ http://photojournal.jpl.nasa.gov/catalog/ PIA02131 ] are that the probe penetrated well below the surface before vaporizing, sending a relatively narrow plume of debris blasting back into space. Researchers are still speculating on the final size of the crater [ http://www.deepimpact.umd.edu/science/ cratering.html ] produced by the July 4th comet crash [ http://www.deepimpact.umd.edu/press/ 050704a-jpl.html ], but material continues to spew from the impact site and has caused the faint comet [ http://deepimpact.umd.edu/collab_pub/imagep.shtml ] to brighten significantly. Determining the crater dimensions and analyzing the debris ejected from the comet's interior will provide premier insights into the formation of comet Tempel 1 [ http://www.deepimpact.umd.edu/science/tempel1.html ], a primordial chunk of our own solar system.
A Swift Look at Tempel 1
Title A Swift Look at Tempel 1
Explanation Comet Tempel 1 is targeted for a collision [ http://antwrp.gsfc.nasa.gov/apod/ap050516.html ] with the impactor probe from NASA's Deep Impact Spacecraft at about 1:52am EDT on July 4th (other time zones [ http://deepimpact.jpl.nasa.gov/faq5.html#q1 ]). Cameras on the impactor probe and the flyby spacecraft will capture close-up images of the event - expected to produce [ http://deepimpact.jpl.nasa.gov/mission/wwws.html ] a crater on the surface of the comet's nucleus. Of course, Earth-orbiting [ http://hubblesite.org/newscenter/newsdesk/archive/ releases/2005/16/ ] and ground-based telescopes will be watching too, including instruments on the Swift satellite normally used to spot gamma-ray bursts [ http://swift.gsfc.nasa.gov/docs/swift/swiftsc.html ] in the distant universe. Swift's ultraviolet telescope recorded this picture of Tempel 1 [ http://swift.gsfc.nasa.gov/docs/swift/results/releases/ images/9P_Tempel1/ ] on June 29th. Because the image is registered on the comet, the background stars appear as short trails. Want to follow the encounter? Media coverage chronicling the event, and the possibilities for viewing the comet [ http://deepimpact.umd.edu/amateur/ ] with small telescopes can be found through the Deep Impact website [ http://deepimpact.jpl.nasa.gov/home/index.html ]. Updated images will also be available from the Kitt Peak National Observatory [ http://www.noao.edu/news/deep-impact/ ].
Tempel 1 and Hartley 2
epoxiimagegallery, nasa
This image shows the nuclei …
500786main_pia13629
mediatype IMAGE
mediatype image
date 2010-11-18
creator NASA
identifier 500786main_pia13629
Gosses Bluff Impact Crater, …
nasa, nasaimageofthedaygalle …
Impact craters, like those w …
ISS007-E-5697_lrg
mediatype IMAGE
mediatype image
date 2003-05-20
creator NASA -- Astronaut photograph eol.jsc.nasa.gov/scripts/sseop/photo.pl?mission=ISS007&roll=E&frame=05697 ISS007-E-05697 was taken with an Electronic Still Camera on May 20, 2003 with a 180-mm lens and is provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC eol.jsc.nasa.gov/ Gateway to Astronaut Photography of Earth.
identifier ISS007-E-5697_lrg
Europa, Ganymede, and Callis …
PIA01656
Jupiter
Solid-State Imaging
Title Europa, Ganymede, and Callisto: Surface comparison at high spatial resolution
Original Caption Released with Image Ganymede's youngest large craters would have been created only about one billion years ago. Europa's surface in this model should be very young, with this satellite being geologically quite active even today. The images were taken by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft. They were processed by the Institute of Planetary Exploration of the German Aerospace Center (DLR) in Berlin, Germany, and scaled to a size of 150 meters per pixel (m/pixel). North is up in all images. The spatial resolution of the original data was 180 m/pixel for Europa and Ganymede and 90 m/pixel for Callisto. The Europa image was taken during Galileo's 6th orbit, the Ganymede image during the 7th, and the Callisto image during the 10th orbit. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]., These images show a comparison of the surfaces of the three icy Galilean satellites, Europa, Ganymede, and Callisto, scaled to a common resolution of 150 meters per picture element (pixel). Despite the similar distance of 0.8 billion kilometers to the sun, their surfaces show dramatic differences. Callisto (with a diameter of 4817 kilometers) is "peppered" by impact craters, but is also covered by a dark material layer of so far unknown origin, as seen here in the region of the Asgard multi-ring basin. It appears that this layer erodes or covers small craters. Ganymede's landscape is also widely formed by impacts, but different from Callisto, much tectonic deformation can be observed in the Galileo images, such as these of Nicholson Regio. Ganymede, with a diameter of 5268 kilometers (one-and-a-half times larger than the Earth's moon), is the largest moon in the solar system. Contrary to Ganymede and Callisto, Europa (diameter 3121 kilometers) has a sparsely cratered surface, indicating that geologic activity took place more recently. Globally, ridged plains and the so-called "mottled terrain" are the main landforms. In the high-resolution image presented here showing the area around the Agave and Asterius dark lineaments, older ridges dominate the surface, while a small part of the younger mottled terrain is visible to the lower left of the image center. While all three moons are believed to be nearly as old as the solar system (4.5 billion years), the age of the surfaces, i.e. the time since the last major geologic activity took place, is still subject to debate. Without having surface samples in hand, the only method to roughly determine a planet's or satellite's geologic surface age is by crater counting. However, assumptions about the impactor fluxes must be made based on theoretical models and possible observations of candidate impactors such as asteroids and comets. Asteroids should have been very common in the early days of the solar system, but this source should have been largely exhausted by about 3.8 billion years before present. For comets, the impactor flux is believed to be rather constant throughout the whole lifetime of the solar system, meaning that the probability of an impact of a large comet is similar today as it was, say, four billion years ago. Assuming the asteroids have been the dominant bodies that impacted the Galilean satellites (which is believed to be the case on the Moon, the Earth, and other inner solar system bodies as well as within the asteroid belt itself), the surfaces of Ganymede and Callisto must be old, roughly four billion years. In this case, the Europan surface would by comparison have a mean age of one-hundred to several-hundred million years. Low-level geologic activity on Europa might be possible, but Ganymede and Callisto should be geologically dead. Assuming on the other hand that comets have been the main impactors in the Jovian system, Callisto's surface would still be determined to be old, but
Moderate-resolution view of …
PIA00898
Jupiter
Solid-State Imaging
Title Moderate-resolution view of Callisto's surface
Original Caption Released with Image This five-frame mosaic of the Jovian satellite Callisto shows a surface densely populated with impact craters. However, close inspection of this image reveals differences among the craters. For example, a few of the craters contain central dome-shaped features, while others contain depressions, or pits, within the crater floor. Scientists study differences among craters such as these to learn more about both the surface that was struck by an impactor, and the impactor itself. These images were obtained by the Galileo spacecraft on its eighth orbit around Jupiter at a distance of 48,000 km from Callisto. The mosaic is centered at 31 S. latitude and 122 W. longitude, and covers an area approximately 700 kilometers (420 miles) by 900 kilometers (540 miles)-- somewhat larger than Montana. The finest details that can be discerned in this picture are about 1.8 kilometers across (0.93 km/pixel). The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo
Tethys and Titan
PIA07705
Saturn
Imaging Science Subsystem - …
Title Tethys and Titan
Original Caption Released with Image Cassini looks toward Tethys and its great crater Odysseus, while at the same time capturing veiled Titan in the distance (at left). Titan (5,150 kilometers, or 3,200 miles across) is shrouded in a thick, smog-like atmosphere in which many small, potential impactors burn up before hitting the moon's surface. Crater-pocked Tethys (1,071 kilometers, or 665 miles across) has no such protective layer, although even a thick blanket of atmosphere would have done little good against the impactor that created Odysseus. The eastern limb of Tethys is overexposed in this view. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Jan. 6, 2006, at a distance of approximately 4 million kilometers (2.5 million miles) from Titan and 2.7 million kilometers (1.7 million miles) from Tethys. The image scale is 25 kilometers (16 miles) per pixel on Titan and 16 kilometers (10 miles) per pixel on Tethys. 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/home/index.cfm [ http://saturn.jpl.nasa.gov ]. The Cassini imaging team homepage is at http://ciclops.org [ http://ciclops.org ].
The Road to Tempel (Artist's …
PIA02106
Sol (our sun)
Title The Road to Tempel (Artist's Concept)
Original Caption Released with Image "" Quick Time Movie for PIA02106 The Road to Tempel This animation chronicles the travels of NASA's Deep Impact spacecraft, from its launch in January of 2005 to its dramatic impact 172 days later with comet Tempel 1. The times listed below were updated on July 2, 2005, and differ from those referred to in the animation. The final phase of the mission, called the encounter phase, includes two targeting maneuvers, the last of which occurs at 5:07 p.m. Pacific time (8:07 p.m. Eastern time), July 2. Six hours later, the spacecraft releases an impactor into the path of the charging comet. Twelve minutes later, the remaining craft, called the flyby, steers itself away from the comet's path. The free impactor then autonomously fine-tunes its trajectory, with the goal of hitting the sunlit side of Tempel 1. Impact is scheduled to occur at 10:52 p.m. Pacific time, July 3 (1:52 a.m. Eastern time, July 4). The flyby spacecraft will watch the collision from the sidelines, snapping pictures up to 13 minutes after impact. At that point, the craft stops taking images and enters a protective mode, in which its shields block dust from the comet's inner coma. Fifty-nine minutes after impact, the flyby turns around for one last photo opportunity.
The Making of Deep Impact
PIA02109
Impactor, S-band Antenna
Title The Making of Deep Impact
Original Caption Released with Image This image shows NASA's Deep Impact spacecraft being built at Ball Aerospace & Technologies Corporation, Boulder, Colo. On July 2, at 10:52 p.m. Pacific time (1:52 a.m. Eastern time, July 3), the spacecraft's impactor will be released from Deep Impact's flyby spacecraft. One day later, it will collide with Tempel 1. The impactor cannot directly talk to Earth, so it will communicate via the flyby spacecraft during its final day. The two spacecraft communicate at "S-band" frequency. The flyby's S-band antenna is the gold, rectangle-shaped object seen on the spacecraft, in the middle of this picture.
A Game of Space Telephone
PIA02110
Impactor, S-band Antenna
Title A Game of Space Telephone
Original Caption Released with Image This image shows NASA's Deep Impact impactor spacecraft while it was being built at Ball Aerospace & Technologies Corporation, Boulder, Colo. On July 2, at 10:52 p.m. Pacific time (1:52 a.m. Eastern time, July 3), the impactor will be released from Deep Impact's flyby spacecraft. One day later, it will collide with Tempel 1. The impactor cannot directly talk to Earth, so it will communicate via the flyby spacecraft during its final day. The two spacecraft communicate at "S-band" frequency. The impactor's S-band antenna is the rectangle-shaped object seen on the top of the impactor in this image.
It Happens in a Flash
PIA02108
Title It Happens in a Flash
Original Caption Released with Image This image shows a flash produced in a laboratory by a high-velocity bead slamming into dust. Though the flash itself can't be resolved, its brilliant effects can be seen in this three-second time exposure. Scientists say that the collision between Deep Impact's impactor and comet Tempel 1 may produce a similar flash. This flash occurred when a quarter-inch sphere smashed into powdered dust at a speed of 6.4 kilometers per second (4 miles per second). Even though the actual flash lasted less than 50 millionths of a second, the camera recorded the hot debris in the impact crater (center) and the streaking ejecta. This experiment was performed at NASA's Ames Research Center, Moffett Field, Calif.
Double Impact
PIA03651
Sol (our sun)
Mars Orbiter Camera
Title Double Impact
Original Caption Released with Image 19 December 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows two craters that formed at the same time by a split meteoritic impactor. Long after they formed, these craters have been eroded, degraded, and other materials have been deposited on and within them. "Location near": 35.0°S, 328.0°W "Image width": width: ~3 km (~1.9 mi)"Illumination from": upper left "Season": Southern Summer
Kittu Dark Ray Crater
PIA01611
Jupiter
Solid-State Imaging
Title Kittu Dark Ray Crater
Original Caption Released with Image View of the dark ray crater Kittu on Jupiter's moon, Ganymede. Kittu is seen in approximately true color, as imaged with the Galileo camera's violet, one micrometer, and near infrared filters. The crater shows a bright white central peak and rim, and dark brownish material surrounding it. Diffuse dark rays, sprinkled thinly atop surrounding grooved terrain, emanate from the impact site. The dark material dusted over the surface is probably part of a dark impactor (asteroid or comet) which was strewn across the surface upon impact. The impactor hit grooved terrain, and a straight segment of the crater's rim was created when a portion of the rim collapsed along the trend of an older fault. North is to the bottom of the picture and the sun illuminates the surface from the left. The mosaic, centered at 0 degrees latitude and 335 degrees longitude, covers an area approximately 70 by 100 kilometers. The resolution in the color portion of this image is about 280 meters per picture element, while the resolution in the black and white portion is 145 meters per picture element. The images were taken beginning on April 5, 1997 from 6 hours, 39 minutes, 46 seconds Universal Time at a range of 14252 kilometers by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://www.jpl.nasa.gov/galileo/sepo [ http://galileo.jpl.nasa.gov/galileo/sepo ]
Craters on South Polar Layer …
PIA09670
Sol (our sun)
HiRISE
Title Craters on South Polar Layered Deposits
Original Caption Released with Image Click on image for larger version This subimage, about 2.5 km across, shows the south polar layered deposits exposed in a scarp illuminated from the lower right. This HiRISE image (PSP_002882_0940 [ http://hirise.lpl.arizona.edu/PSP_002882_0940 ]) was taken in the southern spring, when the surface was completely covered by carbon dioxide frost. Therefore, most of the brightness variations in this scene are caused by topography. The polar layered deposits are broken into blocks by fractures in two directions. Neither set of fractures is parallel to the current scarp face, suggesting that they were not formed as the scarp was eroded, but instead are due to pre-existing weaknesses in the polar layered deposits. The four craters at lower left appear to have formed at the same time by an impactor that broke up as it entered the Martian atmosphere. The presence of many craters such as these on the south polar layered deposits indicates that they are not as young as the north polar layered deposits, which have very few craters on them. Observation Toolbox Acquisition date: 3 March 2007 Local Mars time: 7:06 PM Degrees latitude (centered): -85.9° Degrees longitude (East): 303.4° Range to target site: 246.9 km (154.3 miles) Original image scale range: 24.7 cm/pixel (with 1 x 1 binning) so objects ~74 cm across are resolved Map-projected scale: 25 cm/pixel and north is up Map-projection: POLAR STEREOGRAPHIC Emission angle: 6.7° Phase angle: 78.5° Solar incidence angle: 84°, with the Sun about 6° above the horizon Solar longitude: 196.9°, Northern Autumn NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo.
Craters on South Polar Layer …
PIA09670
Sol (our sun)
HiRISE
Title Craters on South Polar Layered Deposits
Original Caption Released with Image Click on image for larger version This subimage, about 2.5 km across, shows the south polar layered deposits exposed in a scarp illuminated from the lower right. This HiRISE image (PSP_002882_0940 [ http://hirise.lpl.arizona.edu/PSP_002882_0940 ]) was taken in the southern spring, when the surface was completely covered by carbon dioxide frost. Therefore, most of the brightness variations in this scene are caused by topography. The polar layered deposits are broken into blocks by fractures in two directions. Neither set of fractures is parallel to the current scarp face, suggesting that they were not formed as the scarp was eroded, but instead are due to pre-existing weaknesses in the polar layered deposits. The four craters at lower left appear to have formed at the same time by an impactor that broke up as it entered the Martian atmosphere. The presence of many craters such as these on the south polar layered deposits indicates that they are not as young as the north polar layered deposits, which have very few craters on them. Observation Toolbox Acquisition date: 3 March 2007 Local Mars time: 7:06 PM Degrees latitude (centered): -85.9° Degrees longitude (East): 303.4° Range to target site: 246.9 km (154.3 miles) Original image scale range: 24.7 cm/pixel (with 1 x 1 binning) so objects ~74 cm across are resolved Map-projected scale: 25 cm/pixel and north is up Map-projection: POLAR STEREOGRAPHIC Emission angle: 6.7° Phase angle: 78.5° Solar incidence angle: 84°, with the Sun about 6° above the horizon Solar longitude: 196.9°, Northern Autumn NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo.
Craters on South Polar Layer …
PIA09670
Sol (our sun)
HiRISE
Title Craters on South Polar Layered Deposits
Original Caption Released with Image Click on image for larger version This subimage, about 2.5 km across, shows the south polar layered deposits exposed in a scarp illuminated from the lower right. This HiRISE image (PSP_002882_0940 [ http://hirise.lpl.arizona.edu/PSP_002882_0940 ]) was taken in the southern spring, when the surface was completely covered by carbon dioxide frost. Therefore, most of the brightness variations in this scene are caused by topography. The polar layered deposits are broken into blocks by fractures in two directions. Neither set of fractures is parallel to the current scarp face, suggesting that they were not formed as the scarp was eroded, but instead are due to pre-existing weaknesses in the polar layered deposits. The four craters at lower left appear to have formed at the same time by an impactor that broke up as it entered the Martian atmosphere. The presence of many craters such as these on the south polar layered deposits indicates that they are not as young as the north polar layered deposits, which have very few craters on them. Observation Toolbox Acquisition date: 3 March 2007 Local Mars time: 7:06 PM Degrees latitude (centered): -85.9° Degrees longitude (East): 303.4° Range to target site: 246.9 km (154.3 miles) Original image scale range: 24.7 cm/pixel (with 1 x 1 binning) so objects ~74 cm across are resolved Map-projected scale: 25 cm/pixel and north is up Map-projection: POLAR STEREOGRAPHIC Emission angle: 6.7° Phase angle: 78.5° Solar incidence angle: 84°, with the Sun about 6° above the horizon Solar longitude: 196.9°, Northern Autumn NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo.
Large Impact Structures on E …
PIA01661
Jupiter
Solid-State Imaging
Title Large Impact Structures on Europa
Original Caption Released with Image The picture compares four large impact structures on Jupiter's icy moon, Europa. Clockwise, from top left, are Pwyll, Cilix, Tyre, and Mannann'an. Impact structures with diameters of more than 20 kilometers are rather rare on Europa. Tyre is most unusual. While the effective crater, which is somewhat larger than the prominent large bull's eye feature, is about 40 kilometers (25 miles) across, the entire structure is much larger. The concentric rings display relatively little relief. Some of the smaller craters near Tyre were formed by material ejected by and then redeposited from the impact which formed Tyre. One hypothesis for such characteristics is that the impactor which formed Tyre penetrated through an icy crust into a less brittle layer. While Pwyll, Cilix, and Mannann'an also display shallow crater depths for their size, they more closely resemble similar sized craters on two neighboring moons of Jupiter, Ganymede and Callisto. Perhaps the impactor did not punch through the upper crust during these events. This might have been the case if the impacting body was smaller or weaker than in the case of Tyre or if the crust was thinner at the location of Tyre during the impact event. North is to the top of the picture. The sun illuminates the surfaces from the right, except for Tyre, where the sun illuminates the surface from the left. The horizontal and vertical grey lines in the Tyre mosaic indicate gaps in the data received for this image. The Pwyll image was taken on December 16, 1997, Cilix on May 31, 1998,Tyre on March 29, 1998, and Mannann'an on March 29, 1998. All images were taken by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URLhttp://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at URLhttp://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]
Deep Impact on Launch Pad
PIA07292
Title Deep Impact on Launch Pad
Original Caption Released with Image Deep Impact awaits launch from Cape Canaveral Air Force Station, Fla. on Jan. 12, 2005. The spacecraft will travel to comet Tempel 1 and release an impactor, creating a crater on the surface of the comet. Scientists believe the exposed materials may give clues to the formation of our solar system.
A Twisted Tale
PIA08325
Saturn
Imaging Science Subsystem - …
Title A Twisted Tale
Original Caption Released with Image . The Cassini imaging team homepage is at http://ciclops.org [ http://ciclops.org ]., Figure 1 Saturn's D ring--the innermost of the planet's rings -- sports an intriguing structure that appears to be a wavy, or "vertically corrugated," spiral. This continuously changing ring structure provides circumstantial evidence for a possible recent collision event in the rings. Support for this idea comes from the appearance of a structure in the outer D-ring that looks, upon close examination, like a series of bright ringlets with a regularly spaced interval of about 30 kilometers (19 miles). When viewed along a line of sight nearly in the ringplane, a pattern of brightness reversals is observed: a part of the ring that appears bright on the far side of the rings appears dark on the near side of the rings, and vice versa (see PIA08326 [ http://photojournal.jpl.nasa.gov/catalog/PIA08326 ]). This phenomenon would occur if the region contains a sheet of fine material that is vertically corrugated, like a tin roof. In this case, variations in brightness would correspond to changing slopes in the rippled ring material (see figure 1). An observation made with NASA's Hubble Space Telescope in 1995 also saw a periodic structure in the outer D ring, but its wavelength was then 60 kilometers (37 miles). There were insufficient observations to discern the spiral nature of the feature. Thus, it appears the wavelength of the wavy structure has been decreasing: that is, this feature has been winding up like a spring over time. The rate at which the pattern appears to be winding up is quite close to the rate scientists would expect for a vertically corrugated spiraling sheet of material at this location in the rings that is responding to gravitational forcing from Saturn. As Cassini imaging scientists extrapolated the spiraling trend backward in time, they found that it completely unwound in 1984, leaving only an inclined, or tilted, sheet of material. The researchers speculate such an inclined sheet may have been produced around that time by the impact of a comet or meteoroid into the D ring which kicked out a cloud of fine particles that ultimately inherited some of the tilt of the impactor's trajectory as it slammed into the rings. Another possibility is that the impactor struck an already inclined moonlet, shattered it to bits and the debris remained in an inclined orbit. 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/home/index.cfm [ http://saturn.jpl.nasa.gov ]
A Twisted Tale
PIA08325
Saturn
Imaging Science Subsystem - …
Title A Twisted Tale
Original Caption Released with Image . The Cassini imaging team homepage is at http://ciclops.org [ http://ciclops.org ]., Figure 1 Saturn's D ring--the innermost of the planet's rings -- sports an intriguing structure that appears to be a wavy, or "vertically corrugated," spiral. This continuously changing ring structure provides circumstantial evidence for a possible recent collision event in the rings. Support for this idea comes from the appearance of a structure in the outer D-ring that looks, upon close examination, like a series of bright ringlets with a regularly spaced interval of about 30 kilometers (19 miles). When viewed along a line of sight nearly in the ringplane, a pattern of brightness reversals is observed: a part of the ring that appears bright on the far side of the rings appears dark on the near side of the rings, and vice versa (see PIA08326 [ http://photojournal.jpl.nasa.gov/catalog/PIA08326 ]). This phenomenon would occur if the region contains a sheet of fine material that is vertically corrugated, like a tin roof. In this case, variations in brightness would correspond to changing slopes in the rippled ring material (see figure 1). An observation made with NASA's Hubble Space Telescope in 1995 also saw a periodic structure in the outer D ring, but its wavelength was then 60 kilometers (37 miles). There were insufficient observations to discern the spiral nature of the feature. Thus, it appears the wavelength of the wavy structure has been decreasing: that is, this feature has been winding up like a spring over time. The rate at which the pattern appears to be winding up is quite close to the rate scientists would expect for a vertically corrugated spiraling sheet of material at this location in the rings that is responding to gravitational forcing from Saturn. As Cassini imaging scientists extrapolated the spiraling trend backward in time, they found that it completely unwound in 1984, leaving only an inclined, or tilted, sheet of material. The researchers speculate such an inclined sheet may have been produced around that time by the impact of a comet or meteoroid into the D ring which kicked out a cloud of fine particles that ultimately inherited some of the tilt of the impactor's trajectory as it slammed into the rings. Another possibility is that the impactor struck an already inclined moonlet, shattered it to bits and the debris remained in an inclined orbit. 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/home/index.cfm [ http://saturn.jpl.nasa.gov ]
Asymmetric Crater
PIA04945
Sol (our sun)
Thermal Emission Imaging Sys …
Title Asymmetric Crater
Original Caption Released with Image Released 18 December 2003 Asymmetric craters such as the one in the center of this image are fairly rare. The more typical symmetric craters are formed when meteors impact a surface over a wide range of angles. Only very low impact angles (within 15° of horizontal) result in asymmetric structures such as this one. The bilateral symmetry of the ejecta, like two wings on either side of the elliptical crater, is typical of oblique impacts. The small crater downrange from the main crater could have been caused by the impactor breaking apart before impact or possibly a 'decapitation' of the impactor as it hit with the 'head' traveling farther to form the smaller structure. Image information: VIS instrument. Latitude -8.5, Longitude 227.5 East (132.5 West). 19 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.
Asymmetric Crater
PIA04945
Sol (our sun)
Thermal Emission Imaging Sys …
Title Asymmetric Crater
Original Caption Released with Image Released 18 December 2003 Asymmetric craters such as the one in the center of this image are fairly rare. The more typical symmetric craters are formed when meteors impact a surface over a wide range of angles. Only very low impact angles (within 15° of horizontal) result in asymmetric structures such as this one. The bilateral symmetry of the ejecta, like two wings on either side of the elliptical crater, is typical of oblique impacts. The small crater downrange from the main crater could have been caused by the impactor breaking apart before impact or possibly a 'decapitation' of the impactor as it hit with the 'head' traveling farther to form the smaller structure. Image information: VIS instrument. Latitude -8.5, Longitude 227.5 East (132.5 West). 19 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.
Wild Duck Cluster
PIA07878
Impactor Target Sensor Camer …
Title Wild Duck Cluster
Original Caption Released with Image On April 7, 2005, the Deep Impact spacecraft's Impactor Target Sensor camera recorded this image of M11, the Wild Duck cluster, a galactic open cluster located 6 thousand light years away. The camera is located on the impactor spacecraft, which will image comet Tempel 1 beginning 22 hours before impact until about 2 seconds before impact. Impact with comet Tempel 1 is planned for July 4, 2005.
Venus - Lakshmi Region
PIA00082
Sol (our sun)
Imaging Radar
Title Venus - Lakshmi Region
Original Caption Released with Image This Magellan image is centered at 55 degrees north latitude, 348.5 degrees longitude, in the eastern Lakshmi region of Venus. This image, which is of an area 300 kilometers (180 miles) in width and 230 kilometers (138 miles) in length, is a mosaic of orbits 458 through 484. The image shows a relatively flat plains region composed of many lava flows. The dark flows mostly likely represent smooth lava flows similar to 'pahoehoe' flows on Earth while the brighter lava flows are rougher flows similar to 'aa' flows on Earth. (The terms 'pahoehoe' and 'aa' refer to textures of lava with pahoehoe a smooth or ropey surface, and aa a rough, clinkery texture). The rougher flows are brighter because the rough surface returns more energy to the radar than the smooth flows. Situated on top of the lava flows are three dark splotches. Because of the thick Venusian atmosphere, the small impactors break up before they reached the surface. Only the fragments from the broken up impactor are deposited on the surface and these fragments produce the dark splotches in this image. The splotch at the far right (east) has a crater centered in it, indicating that the impactor was not completely destroyed during its journey through the atmosphere. The dark splotches in the center and to the far left in this image each represent an impactor that was broken up into small fragments that did not penetrate the surface to produce a crater. The dark splotch at the left has been modified by the wind. A southwest northeast wind flow has moved some of the debris making up the splotch to the northeast where it has piled up against some small ridges.
Venus - Impact Crater in Eas …
PIA00474
Sol (our sun)
Imaging Radar
Title Venus - Impact Crater in Eastern Navka Region
Original Caption Released with Image This Magellan image, which is 50 kilometers (31 miles) in width and 80 kilometers (50 miles) in length, is centered at 11.9 degrees latitude, 352 degrees longitude in the eastern Navka Region of Venus. The crater, which is approximately 8 kilometers (5 miles) in diameter, displays a butterfly symmetry pattern. The ejecta pattern most likely results from an oblique impact, where the impactor came from the south and ejected material to the north.
Venus - Complex Crater 'Dick …
PIA00479
Sol (our sun)
Imaging Radar
Title Venus - Complex Crater 'Dickinson' in NE Atalanta Region
Original Caption Released with Image This Magellan image is centered at 74.6 degrees north latitude and 177.3 east longitude, in the northeastern Atalanta Region of Venus. The image is approximately 185 kilometers (115 miles) wide at the base and shows Dickinson, an impact crater 69 kilometers (43 miles) in diameter. The crater is complex, characterized by a partial central ring and a floor flooded by radar-dark and radar-bright materials. Hummocky, rough-textured ejecta extend all around the crater, except to the west. The lack of ejecta to the west may indicate that the impactor that produced the crater was an oblique impact from the west. Extensive radar-bright flows that emanate from the crater's eastern walls may represent large volumes of impact melt, or they may be the result of volcanic material released from the subsurface during the cratering event.
Khensu Crater on Ganymede
PIA01090
Jupiter
Solid-State Imaging
Title Khensu Crater on Ganymede
Original Caption Released with Image The dark-floored crater, Khensu, is the target of this image of Ganymede. The solid state imaging camera on NASA's Galileo spacecraft imaged this region as it passed Ganymede during its second orbit through the Jovian system. Khensu is located at 2 degrees latitude and 153 degrees longitude in a region of bright terrain known as Uruk Sulcus, and is about 13 kilometers (8 miles) in diameter. Like some other craters on Ganymede, it possesses an unusually dark floor and a bright ejecta blanket. The dark component may be residual material from the impactor that formed the crater. Another possibility is that the impactor may have punched through the bright surface to reveal a dark layer beneath. Another large crater named El is partly visible in the top-right corner of the image. This crater is 54 kilometers (34 miles) in diameter and has a small "pit" in its center. Craters with such a "central pit" are common across Ganymede and are especially intriguing since they may reveal secrets about the structure of the satellite's shallow subsurface. North is to the top-left of the picture and the sun illuminates the surface from nearly overhead. The image covers an area about 100 kilometers (62 miles) by 86 kilometers (54 miles) across at a resolution of 111 meters (370 feet) per picture element. The image was taken on September 6, 1996 by the solid state imaging (CCD) system on NASA's Galileo spacecraft. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech). This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov.
We're Going In!
PIA02125
Sol (our sun)
Impactor Targeting Sensor
Title We're Going In!
Original Caption Released with Image "" Quick Time Movie for PIA02125 We're Going In! This movie shows Deep Impact's impactor probe approaching comet Tempel 1. It is made up of images taken by the probe's impactor targeting sensor. The probe collided with the comet at10:52 p.m. Pacific time, July 3 (1:52 a.m. Eastern time, July 4).
Impactor Eyes Comet Target
PIA02116
Sol (our sun)
Impactor Targeting Sensor
Title Impactor Eyes Comet Target
Original Caption Released with Image Comet Tempel 1 as seen by the Deep Impact impactor targeting sensor at 7:44 Universal Time, July 3, 2005. This image was taken 1 hour and 37 minutes after the impactor was released from the flyby craft and is displayed on a logarithmic scale. The impactor was 808,478 kilometers (502,388 miles) away from the comet when the image was taken.
Separation Anxiety Over for …
PIA02115
Sol (our sun)
Medium Resolution Imager (MR …
Title Separation Anxiety Over for Deep Impact
Original Caption Released with Image This image of Deep Impact's impactor probe was taken by the mission's mother ship, or flyby spacecraft, after the two separated at 11:07 p.m. Pacific time, July 2 (2:07 a.m. Eastern time, July 3). The impactor is scheduled to collide with comet Tempel 1 at 10:52 p.m. Pacific time, July 3 (1:52 a.m. Eastern time, July 4). The impactor can be seen at the center of the image.
So Close You Can Almost Touc …
PIA02128
Sol (our sun)
Impactor Targeting Sensor
Title So Close You Can Almost Touch It
Original Caption Released with Image This image shows the view from Deep Impact's probe 90 seconds before it was pummeled by comet Tempel 1. The image was taken by the probe's impactor targeting sensor.
Blinded by the Jets
PIA02126
Sol (our sun)
Impactor Targeting Sensor
Title Blinded by the Jets
Original Caption Released with Image This image shows the view from Deep Impact's probe 30 minutes before it was pummeled by comet Tempel 1. The picture's brightness has been enhanced to show the jets of dust streaming away from the comet. The image was taken by the probe's impactor targeting sensor.
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