|
|
Gorgonum Crater Mars Global
…
Numerous deep channels desce
…
6/29/00
| Date |
6/29/00 |
| Description |
Numerous deep channels descending a Martian crater wall, and the debris they left behind, are seen in this mosaic of two images taken by the camera on NASA's Mars Global Surveyor. The area shown is the northwestern wall of an approximately 12 kilometer- (7.4 mile-) wide meteor crater east of the Gorgonum Chaos region in the Martian southern hemisphere. These are deep channels and the number of them and the debris they left behind indicate that as many as tens to hundreds of individual events involving the flow of water and debris have occurred here. The channels and the debris areas look sharp and there are no small meteor impact craters on them, suggesting that these features are extremely young relative to the 4.5 billion-year history of Mars. It is possible that these landforms are still being created by water seeping from the layered rock in the crater wall today. This is a mosaic of pictures taken by Mars Global Surveyor on April 26, 2000, and May 22, 2000. The scene covers an area approximately 4 kilometers (2.5 miles) wide by 7.2 kilometers (4.5 miles) long. Sunlight illuminates the scene from the upper left. The image is located near 37.4 degrees South by 168.0 degrees West. The Mars Orbiter camera high-resolution images are taken in black-and- white (grayscale), the color seen here has been synthesized from the colors of Mars observed by the spacecraft's wide-angle cameras and by the Viking Orbiters in the late 1970s. The Mars Global Surveyor mission is managed for NASA's Office of Space Science by the Jet Propulsion Laboratory, Pasadena, Calif. JPL is a division of the California Institute of Technology. ##### Images Credit: NASA/JPL/Malin Space Science Systems |
|
MARS GLOBAL SURVEYOR CAPTURE
…
NASA's Mars Global Surveyor
…
11/17/00
| Date |
11/17/00 |
| Description |
NASA's Mars Global Surveyor spacecraft, currently orbiting Mars, simultaneously snapped both a wide-angle and high-resolution view of Hale crater that show gullies -- possibly carved by water -- in the peaks of sand dunes inside the crater. The Global Surveyor images, which support findings release last spring, are available at http://photojournal.jpl.nasa.gov , http://mars.jpl.nasa.gov/mgs or http://www.msss.com/mars_images/moc/nov_00_hale/ . Mars Global Surveyor is managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology, Pasadena. |
|
Martian Sedimentary Rock Out
…
Hundreds of layers of sedime
…
12/4/00
| Date |
12/4/00 |
| Description |
Hundreds of layers of sedimentary rock exposed by erosion on the floor of a 64 kilometer-wide (40 mile-wide) meteor crater in western Arabia Terra, Mars, attest to a dynamic early history for the red planet. This high-resolution image from NASA's Mars Global Surveyor spacecraft shows an example enhanced by dark, windblown sand banked up against scarps 5-10 meters high (5-11 yards) formed by eroded rock layers. The west Arabia Terra crater is located at 8 degrees north, 7 degrees west, on the Martian surface. The layers provide a record of repeated, episodic changes that took place at some time far in the Martian past. Mars Global Surveyor is managed for NASA's Office of Space Science, Washington, D.C., by the Jet Propulsion Laboratory, Pasadena, Calif. JPL is a division of the California Institute of Technology. Malin Space Science Systems, San Diego, Calif., built and operates the camera system. JPL's industrial partner is Lockheed Martin Astronautics, Denver, Colo., which developed and operates the spacecraft. ##### |
|
Crater Wall In Noachis Mars
…
Signs of water erosion and d
…
6/29/00
| Date |
6/29/00 |
| Description |
Signs of water erosion and debris flow are seen in this high resolution view of gullies eroded into the wall of a meteor impact crater in Noachis Terra on Mars, taken by NASA's Mars Global Surveyor. The image shows channels and associated aprons of debris, interpreted to have formed by groundwater seepage, surface runoff, and debris flow. The lack of small craters superimposed on the channels and apron deposits indicates that these features are geologically young. It is possible that these gullies indicate that liquid water is present the below the surface of Mars today. This picture was acquired by Mars Global Surveyor on September 28, 1999. The scene covers an area approximately 3 kilometers (about 2 miles) wide by 6.7 kilometers (4.1 miles) high. Sunlight illuminates this area from the upper left. The area covered in the image is located near 54.8 degrees South by 342.5 degrees West. The Mars Orbiter camera high-resolution images are taken in black-and-white (grayscale), the color seen here has been synthesized from the colors of Mars observed by the spacecraft's wide-angle cameras and by NASA's Viking Orbiters in the late 1970s. The Mars Global Surveyor mission is managed for NASA's Office of Space Science by the Jet Propulsion Laboratory, Pasadena, Calif. JPL is a division of the California Institute of Technology. ##### Images Credit: NASA/JPL/Malin Space Science Systems |
|
Phobos' Stickney Crater
| title |
Phobos' Stickney Crater |
| date |
08.19.1998 |
| description |
This image of Phobos, the inner and larger of the two moons of Mars, was taken by Mars Global Surveyor in 1998. This image shows a close-up of the largest crater on Phobos, Stickney, 10 kilometers in diameter. Individual boulders are visible on the near rim of the crater, and are presumed to be ejecta blocks from the impact that formed Stickney. Some of these boulders are enormous, more than 50 meters across. Also crossing at and near the rim of Stickney are shallow, elongated depressions called grooves. This crater is nearly half the size of Phobos, and these grooves may be fractures caused by its formation. Phobos was observed by both the Mars Orbiter Camera (MOC) and Thermal Emission Spectrometer (TES). This image is one of the highest-resolution images (4 meters per pixel) ever obtained of the martian satellite. *Image Credit*: NASA, Jet Propulsion Laboratory, Malin Space Science Systems |
|
High-Resolution MOC Image of
…
| title |
High-Resolution MOC Image of Phobos |
| date |
08.19.1998 |
| description |
This image of Phobos, the inner and larger of the two moons of Mars, was taken by the Mars Global Surveyor on August 19, 1998. This image shows a close-up of the largest crater on Phobos, Stickney, 10 kilometers (6 miles) in diameter. Individual boulders are visible on the near rim of the crater, and are presumed to be ejecta blocks from the impact that formed Stickney. Some of these boulders are enormous - more than 50 meters (160 feet) across. Also crossing at and near the rim of Stickney are shallow, elongated depressions called grooves. This crater is nearly half the size of Phobos and these grooves may be fractures caused by its formation. Phobos was observed by both the Mars Orbiter Camera (MOC) and Thermal Emission Spectrometer (TES). This image is one of the highest resolution images (4 meters or 13 feet per picture element or pixel) ever obtained of the Martian satellite. Malin Space Science Systems, Inc. and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Thermal Emission Spectrometer is operated by Arizona State University and was built by Raytheon Santa Barbara Remote Sensing. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO. *Image Credit*: Erich Karkoschka (University of Arizona Lunar & Planetary Lab) and NASA |
|
'Happy Face' Crater
| title |
'Happy Face' Crater |
| date |
03.10.1999 |
| description |
Mars Global Surveyor was greeted with this view of 'Happy Face Crater' smiling back at its camera from its location on the east side of Argyre Planitia. This crater is officially known as Galle Crater, and it is about 215 kilometers (134 miles) across. The picture was taken by the MOC's red and blue wide angle cameras. The bluish-white tone is caused by wintertime frost. Illumination is from the upper left. For more information and Viking Orbiter views of "Happy Face Crater," see http://www.msss.com/education/happy_face/happy_face.html. *Image Credit*: NASA |
|
Mars River Delta?
| title |
Mars River Delta? |
| description |
A high-resolution TIFF file of this image is available at http://photojournal.jpl.nasa.gov/catalog/PIA04869. Details in a fan-shaped deposit discovered by NASA's Mars Global Surveyor orbiter provide evidence that some ancient rivers on Mars flowed for a long time, not just in brief, intense floods. The apron of debris filling the middle of this picture from the spacecraft's Mars Orbiter Camera is a hardened and eroded distributory fan, a type of geological feature that includes river deltas and alluvial fans. Sediments transported through valleys by water on early Mars formed the 13-kilometer-long (8-mile) deposit in the distant past, when it was still possible for liquid water to flow across the martian surface. Mars Orbiter Camera team members published discovery of this feature in the online edition of the journal Science. What is important about it? First, it provides unequivocal evidence that some valleys on Mars experienced persistent flow over considerable periods of time, as rivers do on Earth. Second, because the fan is today a deposit of sedimentary rock, it demonstrates that some sedimentary rocks on Mars were deposited in a liquid environment. Third, the fan's general shape, the pattern of its channels, and its low slopes provide circumstantial evidence that the feature was an actual delta -- that is, a deposit made when a river or stream enters a body of water. If so, this landform is a strong indicator that some craters and basins on Mars once held lakes. Hundreds of other locations on Mars where valleys enter craters and basins have been imaged by the Mars Orbiter Camera, but none has shown landforms like those presented here. The picture is a mosaic of images acquired between August 2000 and September 2003. The area covered 14 kilometer (8.7 miles) by 19.3 kilometers (12 miles). North is up. Sunlight illuminates the scene from the left. The spacecraft's narrow-angle camera takes grayscale images, the color added is based on information from a camera on Mars Odyssey. The fan is in an unnamed crater that is 64 kilometers (40 miles) in diameter, at 24.3 degrees south latitude, 33.5 degrees west longitude. The crater lies northeast of a larger one named Holden Crater. The fan is a fossil landform. That is, it is an eroded remnant of a somewhat larger and thicker deposit. The originally loose sediment was turned to rock and then eroded over time to present the features seen today. The channels through which sediment was transported are no longer present. Instead, only their floors remain, and these have been elevated by erosion so that former channels now stand as ridges. The floors of former channels became inverted in this way because they were more resistant to the forces of erosion, indicating they either were more strongly cemented than surrounding materials, or they have more coarse grains (which are harder to remove), or both. *Image Credit*: NASA/JPL/Malin Space Science Systems |
|
New Gullies on Martian Sand
…
| title |
New Gullies on Martian Sand Dune |
| description |
As part of extended-mission science investigation using the Mars Orbiter Camera on NASA's Mars Global Surveyor spacecraft, the camera team is re-imaging many locations where previous observations revealed gullies. The intent is to see if gully-forming processes are operating on Mars at the present time. The team has found one location where a new gully formed on a dune in an unnamed crater in the Hellespontus region of Mars, west of the Hellas Basin. This pair of narrow-angle images from the Mars Orbiter Camera shows the dune as it appeared on July 17, 2002, (left) and as it appeared on April 27, 2005, (right). The nearly three Earth years of intervening time amount to about 1.4 Mars years. During this period, a couple of gullies formed on the dune slip face. It is critical to recognize that the 2002 image was obtained at a time of year when the incident sunlight was coming in from a lower angle, relative to the horizon, than in the 2005 image. If the gullies had been present in 2002, their appearance would be sharper and more pronounced than they are in the 2005 image. The gullies simply did not exist on July 17, 2002. The steep walls of the gully alcove and channels suggests that the sand in this dune is somewhat cohesive, an observation common among martian sand dunes seen by the Mars Orbiter Camera over the past eight years. Image Credit: NASA/JPL/MSSS |
|
Evidence of Martian Quakes
| title |
Evidence of Martian Quakes |
| description |
One of the many mysteries associated with martian geology is the origin of gullies found at latitudes poleward of 30 degrees latitude. Most of these gullies are found within craters or other depressions, and appear to be related to the bedrock. Several hypotheses have been proposed for their origin, including groundwater seepage and melting at the base of a dust-mantled snow pack. Some middle-latitude gullies are found on sand dunes. These gullies appear to be different from those found on the slopes of craters, but generally have been interpreted to form by similar processes. In the present martian environment, it is difficult to introduce water to the surface. The temperature and atmospheric pressure may permit water to exist, but the rate of heating of the ground and atmosphere, and the amount of energy available to warm the ground or melt snow, are not conducive to such processes. An alternative process of gully formation on these sand dunes involves frozen carbon dioxide trapped in the winter by windblown sand, then subliming rapidly enough for the escaping carbon-dioxide gas to make the sand flow as a gully-cutting fluid. As part of extended-mission science investigation using the Mars Orbiter Camera on NASA's Mars Global Surveyor spacecraft, the camera team is re-imaging many locations where previous observations revealed gullies. The intent is to see if gully-forming processes are operating on Mars at the present time. The team has found one location where a new gully formed on a dune in an unnamed crater in the Hellespontus region of Mars, west of the Hellas Basin. This pair of narrow-angle images from the Mars Orbiter Camera shows the dune as it appeared on July 17, 2002, (left) and as it appeared on April 27, 2005, (right). The nearly three Earth years of intervening time amount to about 1.4 Mars years. During this period, a couple of gullies formed on the dune slip face. It is critical to recognize that the 2002 image was obtained at a time of year when the incident sunlight was coming in from a lower angle, relative to the horizon, than in the 2005 image. If the gullies had been present in 2002, their appearance would be sharper and more pronounced than they are in the 2005 image. The gullies simply did not exist on July 17, 2002. The steep walls of the gully alcove and channels suggests that the sand in this dune is somewhat cohesive, an observation common among martian sand dunes seen by the Mars Orbiter Camera over the past eight years. Wider context for the dune is shown in a mosaic of two images from the Thermal Emission Imaging System on NASA's Mars Odyssey orbiter, encompassing the dark-toned sand dune field on the floor of a crater located near 49.8 degrees south latitude, 325.4 degrees west longitude. In this image, north is approximately up and sunlight illuminates the scene from the upper left. More information about this image can be found at: http://photojournal.jpl.nasa.gov/catalog/PIA04290 |
|
Mars and Syrtis Major
| Title |
Mars and Syrtis Major |
| Full Description |
Taking advantage of Mars's closest approach to Earth in eight years, astronomers using NASA's Hubble Space Telescope have taken the space- based observatory's sharpest views yet of the Red Planet. The telescope's Wide Field and Planetary Camera 2 snapped these images between April 27 and May 6, when Mars was 54 million miles (87 million kilometers) from Earth. From this distance the telescope could see Martian features as small as 12 miles (19 kilometers) wide. The telescope obtained four images, which, together, show the entire planet. Each view depicts the planet as it completes one quarter of its daily rotation. In these views the north polar cap is tilted toward the Earth and is visible prominently at the top of each picture. The images were taken in the middle of the Martian northern summer, when the polar cap had shrunk to its smallest size. During this season the Sun shines continuously on the polar cap. Previous telescopic and spacecraft observations have shown that this summertime "residual" polar cap is composed of water ice, just like Earth's polar caps. These Hubble telescope snapshots reveal that substantial changes in the bright and dark markings on Mars have occurred in the 20 years since the NASA Viking spacecraft missions first mapped the planet. The Martian surface is dynamic and ever changing. Some regions that were dark 20 years ago are now bright red, some areas that were bright red are now dark. Winds move sand and dust from region to region, often in spectacular dust storms. Over long timescales many of the larger bright and dark markings remain stable, but smaller details come and go as they are covered and then uncovered by sand and dust. The dark feature known as Syrtis Major was first seen telescopically by the astronomer Christiaan Huygens in the 17th century. Many small, dark, circular impact craters can be seen in this region, attesting to the Hubble telescope's ability to reveal fine detail on the planet's surface. To the south of Syrtis is a large circular feature called Hellas. Viking and more recently Mars Global Surveyor have revealed that Hellas is a large and deep impact crater. These Hubble telescope pictures show it to be filled with surface frost and water ice clouds. Along the right limb, late afternoon clouds have formed around the volcano Elysium. |
| Date |
06/30/1999 |
| NASA Center |
Hubble Space Telescope Center |
|
Evidence for Recent Liquid W
…
| Title |
Evidence for Recent Liquid Water on Mars |
| Full Description |
Newton Crater is a large basin formed by an asteroid impact that probably occurred more than 3 billion years ago. It is approximately 287 kilometers (178 miles) across. The picture shown here (top) highlights the north wall of a specific, smaller crater located in the southwestern quarter of Newton Crater (above). The crater of interest was also formed by an impact, it is about 7 km (4.4 mi) across, which is about 7 times bigger than the famous Meteor Crater in northern Arizona in North America. The north wall of the small crater has many narrow gullies eroded into it. These are hypothesized to have been formed by flowing water and debris flows. Debris transported with the water created lobed and finger-like deposits at the base of the crater wall where it intersects the floor (bottom center top image). Many of the finger-like deposits have small channels indicating that a liquid, most likely water, flowed in these areas. Hundreds of individual water and debris flow events might have occurred to create the scene shown here. Each outburst of water from higher up on the crater slopes would have constituted a competition between evaporation, freezing, and gravity. The individual deposits at the ends of channels in this MOC image mosaic were used to get a rough estimate of the minimum amount of water that might be involved in each flow event. This is done first by assuming that the deposits are like debris flows on Earth. In a debris flow, no less than about 10% (and no more than 30%) of their volume is water. Second, the volume of an apron deposit is estimated by measuring the area covered in the MOC image and multiplying it by a conservative estimate of thickness, 2 meters (6.5 feet). For a flow containing only 10% water, these estimates conservatively suggest that about 2.5 million liters (660,000 gallons) of water are involved in each event, this is enough to fill about 7 community-sized swimming pools or enough to supply 20 people with their water needs for a year. The Mars Orbiter Camera (MOC) high resolution view is located near 41.1S, 159.8W and is a mosaic of three different pictures acquired between January and May 2000. The MOC scene is illuminated from the left, north is up. |
| Date |
06/22/2000 |
| NASA Center |
Jet Propulsion Laboratory |
|
Evidence for Recent Liquid W
…
| Title |
Evidence for Recent Liquid Water on Mars |
| Full Description |
Gullies eroded into the wall of a meteor impact crater in Noachis Terra. This high resolution view (top left) from the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) shows channels and associated aprons of debris that are interpreted to have formed by groundwater seepage, surface runoff, and debris flow. The lack of small craters superimposed on the channels and apron deposits indicates that these features are geologically young. It is possible that these gullies indicate that liquid water is present within the martian subsurface today. The MOC image was acquired on September 28, 1999. The scene covers an area approximately 3 kilometers (1.9 miles) wide by 6.7 km (4.1 mi) high (note, the aspect ratio is 1.5 to 1.0). Sunlight illuminates this area from the upper left. The image is located near 54.8S, 342.5W. The context image (above) shows the location of the MOC image on the south-facing wall of an impact crater approximately 20 kilometers (12 miles) in diameter. The context picture was obtained by the Viking 1 orbiter in 1980 and is illuminated from the upper left. The large mound on the floor of the crater in the context view is a sand dune field. The Mars Orbiter Camera high resolution images are taken black-and-white (grayscale), the color seen here has been synthesized from the colors of Mars observed by the MOC wide angle cameras and by the Viking Orbiters in the late 1970s. A brief description of how the color was generated: The MOC narrow angle camera only takes grayscale (black and white) pictures. To create the color versions seen here, we have taken much lower resolution red and blue images acquired by the MOC's wide angle cameras, and by the Viking Orbiter cameras in the 1970s, synthesized a green image by averaging red and blue, and created a pallete of colors that represent the range of colors on Mars. We then use a relationship that correlates color and brightness to assign a color to each gray level. This is only a crude approximation of martian color. It is likely Mars would not look like this to a human observer at Mars. |
| Date |
06/22/2000 |
| NASA Center |
Jet Propulsion Laboratory |
|
A Closer Encounter with Mars
| Title |
A Closer Encounter with Mars |
|
Fly up to Sasquatch Crater v
…
| Title |
Fly up to Sasquatch Crater view one |
| Completed |
1998-12-02 |
|
Hellas Crater Flat Flyover (
…
| Title |
Hellas Crater Flat Flyover (True Color) |
| Completed |
1999-05-24 |
|
Mars Hellas Crater Flat Flyo
…
| Title |
Mars Hellas Crater Flat Flyover (False Color) |
| Abstract |
Hellas Crater Flat Flyover (False Color). Based on MOLA data. |
| Completed |
1999-05-24 |
|
Mars Hellas Crater - Flat Sp
…
| Title |
Mars Hellas Crater - Flat Spin (False Color) |
| Abstract |
Hellas Crater Flat Spin (False Color) |
| Completed |
1999-05-24 |
|
Mars Hellas Crater - Flat Sp
…
| Title |
Mars Hellas Crater - Flat Spin (False Color) |
| Abstract |
Hellas Crater Flat Spin (False Color) |
| Completed |
1999-05-24 |
|
Mars Hellas Crater - Flat Sp
…
| Title |
Mars Hellas Crater - Flat Spin (False Color) |
| Abstract |
Hellas Crater Flat Spin (False Color) |
| Completed |
1999-05-24 |
|
MOLA-based Flyover of Korole
…
| Title |
MOLA-based Flyover of Korolev Crater |
| Abstract |
MOLA-based animations showing Martian topography as both color and elevation. The exaggeration is 3x. This was created for a talk James Garvin will give on The Hill in late April 2002. |
| Completed |
2002-04-16 |
|
Great Zoom into Distributary
…
| Title |
Great Zoom into Distributary Fan, Mars |
| Abstract |
This is a Great Zoom into the so-called Distributary Fan on Mars. It is located just northeast of Holden Crater. As seen from Martian orbit by the Mars Orbiter Camera (MOC) flying on the Mars Globel Surveyor (MGS) spacecraft, this dramatic visualization shows us where liquid water likely flowed across the Martian surface sometime in the planet's past. |
| Completed |
2003-12-18 |
|
Great Zoom into Distributary
…
| Title |
Great Zoom into Distributary Fan, Mars |
| Abstract |
This is a Great Zoom into the so-called Distributary Fan on Mars. It is located just northeast of Holden Crater. As seen from Martian orbit by the Mars Orbiter Camera (MOC) flying on the Mars Globel Surveyor (MGS) spacecraft, this dramatic visualization shows us where liquid water likely flowed across the Martian surface sometime in the planet's past. |
| Completed |
2003-12-18 |
|
Great Zoom into Distributary
…
| Title |
Great Zoom into Distributary Fan, Mars |
| Abstract |
This is a Great Zoom into the so-called Distributary Fan on Mars. It is located just northeast of Holden Crater. As seen from Martian orbit by the Mars Orbiter Camera (MOC) flying on the Mars Globel Surveyor (MGS) spacecraft, this dramatic visualization shows us where liquid water likely flowed across the Martian surface sometime in the planet's past. |
| Completed |
2003-12-18 |
|
Great Zoom into Distributary
…
| Title |
Great Zoom into Distributary Fan, Mars |
| Abstract |
This is a Great Zoom into the so-called Distributary Fan on Mars. It is located just northeast of Holden Crater. As seen from Martian orbit by the Mars Orbiter Camera (MOC) flying on the Mars Globel Surveyor (MGS) spacecraft, this dramatic visualization shows us where liquid water likely flowed across the Martian surface sometime in the planet's past. |
| Completed |
2003-12-18 |
|
Great Zoom into Distributary
…
| Title |
Great Zoom into Distributary Fan, Mars |
| Abstract |
This is a Great Zoom into the so-called Distributary Fan on Mars. It is located just northeast of Holden Crater. As seen from Martian orbit by the Mars Orbiter Camera (MOC) flying on the Mars Globel Surveyor (MGS) spacecraft, this dramatic visualization shows us where liquid water likely flowed across the Martian surface sometime in the planet's past. |
| Completed |
2003-12-18 |
|
Great Zoom into Distributary
…
| Title |
Great Zoom into Distributary Fan, Mars |
| Abstract |
This is a Great Zoom into the so-called Distributary Fan on Mars. It is located just northeast of Holden Crater. As seen from Martian orbit by the Mars Orbiter Camera (MOC) flying on the Mars Globel Surveyor (MGS) spacecraft, this dramatic visualization shows us where liquid water likely flowed across the Martian surface sometime in the planet's past. |
| Completed |
2003-12-18 |
|
Great Zoom into Distributary
…
| Title |
Great Zoom into Distributary Fan, Mars |
| Abstract |
This is a Great Zoom into the so-called Distributary Fan on Mars. It is located just northeast of Holden Crater. As seen from Martian orbit by the Mars Orbiter Camera (MOC) flying on the Mars Globel Surveyor (MGS) spacecraft, this dramatic visualization shows us where liquid water likely flowed across the Martian surface sometime in the planet's past. |
| Completed |
2003-12-18 |
|
Great Zoom into Distributary
…
| Title |
Great Zoom into Distributary Fan, Mars |
| Abstract |
This is a Great Zoom into the so-called Distributary Fan on Mars. It is located just northeast of Holden Crater. As seen from Martian orbit by the Mars Orbiter Camera (MOC) flying on the Mars Globel Surveyor (MGS) spacecraft, this dramatic visualization shows us where liquid water likely flowed across the Martian surface sometime in the planet's past. |
| Completed |
2003-12-18 |
|
Great Zoom into Distributary
…
| Title |
Great Zoom into Distributary Fan, Mars |
| Abstract |
This is a Great Zoom into the so-called Distributary Fan on Mars. It is located just northeast of Holden Crater. As seen from Martian orbit by the Mars Orbiter Camera (MOC) flying on the Mars Globel Surveyor (MGS) spacecraft, this dramatic visualization shows us where liquid water likely flowed across the Martian surface sometime in the planet's past. |
| Completed |
2003-12-18 |
|
Great Zoom into Distributary
…
| Title |
Great Zoom into Distributary Fan, Mars |
| Abstract |
This is a Great Zoom into the so-called Distributary Fan on Mars. It is located just northeast of Holden Crater. As seen from Martian orbit by the Mars Orbiter Camera (MOC) flying on the Mars Globel Surveyor (MGS) spacecraft, this dramatic visualization shows us where liquid water likely flowed across the Martian surface sometime in the planet's past. |
| Completed |
2003-12-18 |
|
Great Zoom into Distributary
…
| Title |
Great Zoom into Distributary Fan, Mars |
| Abstract |
This is a Great Zoom into the so-called Distributary Fan on Mars. It is located just northeast of Holden Crater. As seen from Martian orbit by the Mars Orbiter Camera (MOC) flying on the Mars Globel Surveyor (MGS) spacecraft, this dramatic visualization shows us where liquid water likely flowed across the Martian surface sometime in the planet's past. |
| Completed |
2003-12-18 |
|
Great Zoom into Distributary
…
| Title |
Great Zoom into Distributary Fan, Mars |
| Abstract |
This is a Great Zoom into the so-called Distributary Fan on Mars. It is located just northeast of Holden Crater. As seen from Martian orbit by the Mars Orbiter Camera (MOC) flying on the Mars Globel Surveyor (MGS) spacecraft, this dramatic visualization shows us where liquid water likely flowed across the Martian surface sometime in the planet's past. |
| Completed |
2003-12-18 |
|
MOLA-based Flyover of Gusev
…
| Title |
MOLA-based Flyover of Gusev Crater |
| Abstract |
MOLA-based animations showing Martian topography as both color and elevation. The exaggeration is 3x. This was created for a talk James Garvin will give on The Hill in late April 2002. |
| Completed |
2002-04-16 |
|
Earth and Moon as Viewed fro
…
| Title |
Earth and Moon as Viewed from Mars |
| Description |
This is the first image of Earth ever taken from another planet that actually shows our home as a planetary disk. Because Earth and the Moon are closer to the Sun than Mars, they exhibit phases, just as the Moon, Venus, and Mercury do when viewed from Earth. As seen from Mars by the NASA Mars Global Surveyor on May 8, 2003, at 13:00 GMT (6:00 a.m. PDT), Earth and the Moon appeared in the evening sky. This Earth/Moon image has been specially processed to allow both Earth (with an apparent magnitude of -2.5) and the much darker Moon (with an apparent magnitude of +0.9) to be visible together. The bright area at the top of the image of Earth is cloud cover over central and eastern North America. Below that, a darker area includes Central America and the Gulf of Mexico. The bright feature near the center right of the crescent Earth consists of clouds over northern South America. The image also shows the Earth-facing hemisphere of the Moon, since the Moon was on the far side of Earth as viewed from Mars. The slightly lighter tone of the lower portion of the image of the Moon results from the large and conspicuous ray system associated with the crater Tycho. A note about the coloring process: The Mars Global Surveyor Mars Orbital Camera (MOC, a high-resolution camera) only takes grayscale (black-and-white) images. To "colorize" the image, a Mariner 10 Earth/Moon image taken in 1973 was used to color this Earth and Moon picture. The procedure used was as follows: the Mariner 10 image was converted from 24-bit color to 8-bit color using a JPEG to GIF conversion program. The 8-bit color image was converted to 8-bit grayscale and an associated lookup table mapping each gray value of the image to a red-green-blue color triplet (RGB). Each color triplet was root-sum-squared (RSS), and sorted in increasing RSS values. These sorted lists were brightness-to-color maps for the images. Each brightness-to-color map was then used to convert the 8-bit grayscale MOC image to an 8-bit color image. This 8-bit color image was then converted to a 24-bit color image. The color image was edited to return the background to black. Image courtesy NASA/JPL/Malin Space Science Systems [ http://www.msss.com/ ] |
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Aeolian Mars
| Title |
Aeolian Mars |
| Explanation |
Mars' [ http://mars.ivv.nasa.gov/resources/mars_data-information/ mars_earth_comp_NSSDC_and.html ]atmosphere is relatively thin, still when martian winds [ http://antwrp.gsfc.nasa.gov/apod/ap990520.html ] blow they weather [ http://learn.jpl.nasa.gov/projectspacef/weather.html ] and shape its surface [ http://www.msss.com/mars_images/moc/1_31_00_dunes/index.html ]. Like familiar aeolian [ http://darkwing.uoregon.edu/~millerm/DVdune1.html ] features on Earth [ http://ruidoso.net/chamber/outdoors/whitesan.html ], this field of dunes within Mars' Rabe crater exhibits graceful undulating ridges [ http://photo.net/photo/pcd0738/great-sand-dune-ridge-7.tcl ] which can shift as windblown material is deposited on the dunes' windward face and falls away down the steeper leeward slopes. Indicated by the arrow, the dark trails are signs that the martian [ http://amor.rz.hu-berlin.de/~h0444ihv/private/marslit/marsbib.html ] sand has avalanched down the steep slopes in the recent past. Rippling patterns of smaller dunes are also visible in this sharp high-resolution view [ http://www.msss.com/mars_images/moc/1_31_00_dunes/ rabe_dunes/index.html ] along with criss-crossing dark trails which may be evidence of local dust-devil [ http://www.msss.com/mars_images/moc/8_10_99_releases/ moc2_171/index.html ] windstorms. The image is about 3 kilometers across and was recorded in March of 1999 by the orbiting Mars [ http://www.msss.com/mars_images/moc/1_2000_jan1movie/index.html ] Global Surveyor spacecraft. |
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The Gullies Of Mars
| Title |
The Gullies Of Mars |
| Explanation |
The recently revealed gullies [ http://www.msss.com/mars_images/moc/june2000/ ] on Mars are rare. But they may [ ftp://ftp.hq.nasa.gov/pub/pao/pressrel/2000/00-099.txt ] prove to be sites of present day, near surface, liquid water [ http://cmex-www.arc.nasa.gov/SiteCat/sitecat2/water.htm ], holding out the tantalizing possibility of martian life [ http://cmex-www.arc.nasa.gov/SiteCat/sitecat2/stratex.htm ]. Too small to have been seen by past [ http://mars.jpl.nasa.gov/mep/history/index.html ] Mars orbiters, these disconcerting landforms were found in only about 250 out of more than 20,000 high resolution images from the operating Mars Global Surveyor [ http://mars.jpl.nasa.gov/mgs/images/highres.html ] spacecraft. Gullies found so far are located away from the martian [ http://cmex.arc.nasa.gov/MarsTools/MarsTools.html ] equatorial region at middle and high latitudes (predominately in the south) and on poleward facing slopes. They are disconcerting because researchers have a compelling body of evidence [ http://www.sciencemag.org/feature/data/ hottopics/index.html ] that the martian gullies are related to groundwater seepage and, like their terrestrial counterparts, liquid water runoff -- on a planet [ http://antwrp.gsfc.nasa.gov/apod/ap970627.html ] whose surface is thought to be too cold and atmosphere too thin for liquid water to exist. The gullies in the three kilometer wide area pictured above [ http://www.msss.com/mars_images/moc/june2000/scicover/ index.html ] are in the south facing wall of a crater in southern Noachis Terra [ http://cmex-www.arc.nasa.gov/SiteCat/sitecat2/oasis.htm ]. Unblemished by craters and overlaying young surface features, these and other gullies are inescapably young [ http://www.msss.com/mars_images/moc/june2000/age/ index.html ] themselves. In fact, future [ http://spaceflight.nasa.gov/mars/ ] monitoring of the martian gullies for changes could demonstrate whether the flows that formed them are still active today. |
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Newton Crater: Evidence for
…
| Title |
Newton Crater: Evidence for Recent Water on Mars |
| Explanation |
What could have formed these unusual channels? Inside a small crater [ http://www.jpl.nasa.gov/galileo/sepo/education/plansurf/plansurfii.html ] that lies inside large Newton Crater [ http://ic.arc.nasa.gov/ic/projects/bayes-group/Atlas/Mars/features/n/newton.html ] on Mars [ http://www.seds.org/nineplanets/nineplanets/mars.html ], numerous narrow channels run from the top down to the crater floor. The above picture [ http://www.msss.com/mars_images/moc/june2000/newton/index.html ] covers a region spanning about 3000 meters across. These and other gullies [ http://antwrp.gsfc.nasa.gov/apod/ap000623.html ] have been found on Mars in recent high-resolution pictures [ http://www.msss.com/mars_images/moc/june2000/index.html ] taken by the orbiting Mars Global Surveyor [ http://mars.jpl.nasa.gov/mgs/overvu/overview.html ] robot spacecraft. Similar channels on Earth [ http://www.msss.com/mars_images/moc/june2000/labeled/index.html ] are formed by flowing water, but on Mars the temperature is normally too cold and the atmosphere [ http://windows.ivv.nasa.gov/cgi-bin/tour_def/mars/lower_atmosphere.html ] too thin to sustain liquid water [ http://www.es.mq.edu.au/courses/GEOS112/mod2/worsho/06/6_2.html ]. Nevertheless, many scientists now hypothesize that liquid water did burst out here from underground Mars [ http://antwrp.gsfc.nasa.gov/apod/mars.html ], eroded the gullies, and pooled at the bottom as it froze and evaporated. If so, life-sustaining ice and water [ http://antwrp.gsfc.nasa.gov/apod/ap980530.html ] might exist even today below the Martian surface [ http://antwrp.gsfc.nasa.gov/apod/ap000514.html ] -- water that could potentially support a human mission to Mars [ http://www-sn.jsc.nasa.gov/marsref/contents.html ]. Research into this exciting possibility [ http://www.sciencemag.org/feature/data/hottopics/index.html ] is sure to continue! |
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Light Deposits Indicate Wate
…
| Title |
Light Deposits Indicate Water Flowing on Mars |
| Explanation |
What's creating light-toned deposits on Mars? Quite possibly -- water! Images of the same parts of mid-latitude Mars [ http://antwrp.gsfc.nasa.gov/apod/ap010628.html ] taken over the years but released [ http://www.msss.com/mars_images/moc/2006/12/06/gullies/sirenum_crater/index.html ] only last week have shown unexpected new light-toned deposits where there were none before. One clear case is shown above [ http://photojournal.jpl.nasa.gov/catalog/PIA09028 ], where the same crater on Mars is shown as photographed in 1999 August and again in 2005 September. The unusual deposit is visible only on the more recent photograph. Apparent tributaries near the bottom bolster the leading hypothesis [ http://planetary.org/blog/article/00000789/ ] that water gushed out of the crater wall, flowed down the crater, and soon evaporated into the thin Martian atmosphere [ http://www.daviddarling.info/encyclopedia/M/Marsatmos.html ]. Although frozen water-ice [ http://antwrp.gsfc.nasa.gov/apod/ap050720.html ] has been known near the Martian poles [ http://antwrp.gsfc.nasa.gov/apod/ap981216.html ] for years, free flowing surface water like this was not expected to be seen in the mid-latitudes of Mars [ http://en.wikipedia.org/wiki/Mars ]. If confirmed, such water springs might make more of Mars hospitable to life [ http://mars.jpl.nasa.gov/science/life/ ] and human visitation [ http://www.nasa.gov/mission_pages/exploration/main/index.html ] than previously believed. |
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A Frosty Crater On Mars
| Title |
A Frosty Crater On Mars |
| Explanation |
In the martian [ http://humbabe.arc.nasa.gov/mgcm/faq/ faq.html ] southern hemisphere, autumn has arrived. As on planet Earth, the cooler temperatures bring a seasonal [ http://cmex-www.arc.nasa.gov/MarsEssy/seasons/ seasons.htm ] frost to the landscape. Of course on Mars, the surface temperatures [ http://emma.la.asu.edu/daily.html ] can be really cool [ http://antwrp.gsfc.nasa.gov/apod/ap990602.html ], reaching below minus 100 degrees C. This detailed Mars Global Surveyor synthesized color image [ http://www.msss.com/mars_images/moc/nov_00_craters/ index.html ] of Lowell crater at 52 degrees south martian latitude was recorded on October 17. Whitish frost has begun to accumulate on floor of the 201 kilometer wide crater. The crater's weathered walls suggest Lowell is relatively old. In striking contrast, two smaller, sharp-rimmed young craters are [ http://cmex-www.arc.nasa.gov/MarsEssy/crater.htm ] clearly superimposed on the older features near Lowell's outer rim. |
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Sand Dunes on Mars
| Title |
Sand Dunes on Mars |
| Explanation |
Sand dunes on Mars can appear exotic. The dark dunes above [ http://www.msss.com/mars_images/moc/01_31_01_releases/sharks/index.html ] might be compared to shark's teeth [ http://mgs.dnr.md.gov/esic/brochures/sharks.html ] or chocolate confections [ http://www.exploratorium.edu/chocolate/ ]. In reality, they arise from the complex relationship between the sandy surface [ http://antwrp.gsfc.nasa.gov/apod/ap000514.html ] and high winds [ http://antwrp.gsfc.nasa.gov/apod/ap000514.html ] on Mars. These particular dunes [ http://antwrp.gsfc.nasa.gov/apod/ap980814.html ] are located in Proctor Crater [ http://www.msss.com/mars_images/moc/8_10_99_releases/moc2_170/ ], a 170 kilometer wide crater first seen to house sand dunes by Mariner 9 [ http://nssdc.gsfc.nasa.gov/nmc/tmp/1971-051A.html ] more than 25 years ago. The above picture [ http://www.msss.com/mars_images/moc/01_31_01_releases/sharks/index.html ] was taken by Mars Global Surveyor [ http://mars.jpl.nasa.gov/mgs/ ] (MGS), a robot spacecraft [ http://mars.jpl.nasa.gov/mgs/overvu/overview.html ] currently in orbit around Mars [ http://www.nineplanets.org/mars.html ]. MGS has recently completed a primary goal [ http://www.msss.com/mars_images/moc/01_31_01_releases/index.html ] of taking and transmitting detailed survey images of the red planet [ http://antwrp.gsfc.nasa.gov/apod/mars.html ] over an entire Martian year (669 Earth days). MGS will now be deployed [ http://www.space.com/scienceastronomy/solarsystem/mgs_update_001212.html ] to study particularly interesting regions of Mars [ http://cmex-www.arc.nasa.gov/ ] in more detail. |
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A Hole in Mars Close Up
| Title |
A Hole in Mars Close Up |
| Explanation |
In a close-up [ http://hirise.lpl.arizona.edu/PSP_004847_1745 ] from the HiRISE [ http://hirise.lpl.arizona.edu/index.php ] instrument onboard the Mars Reconnaissance Orbiter, this mysterious dark pit, about 150 meters across, lies on the north slope of ancient martian [ http://www.lukew.com/marsgeo/index.html ] volcano Arsia Mons [ http://photojournal.jpl.nasa.gov/catalog/PIA02337 ]. Lacking raised rims and other impact crater characteristics, this pit and others like it [ http://mars.jpl.nasa.gov/odyssey/newsroom/pressreleases/ 20070921a.html ] were originally identified in visible light and infrared images from the Mars Odyssey and Mars Global Surveyor spacecraft. While the visible light images showed only darkness within [ http://antwrp.gsfc.nasa.gov/apod/ap070528.html ], infrared thermal signatures [ http://www.nasa.gov/mission_pages/odyssey/images/ cave4.html ] indicated that the openings penetrated deep under the martian surface and perhaps were skylights to underground caverns. In this later image, the pit wall is partially illuminated by sunlight and seen to be nearly vertical, though the bottom, at least 78 meters below, is still not visible. The dark martian pits are thought to be related to collapse pits [ http://hvo.wr.usgs.gov/gallery/kilauea/erz/ devilsthroat.html ] in the lava flow, similar [ http://hvo.wr.usgs.gov/gallery/kilauea/erz/ upper/30424305-044_large.jpg ] to Hawaiian volcano pit craters [ http://volcanoes.usgs.gov/Products/Pglossary/ PitCrater.html ]. |
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Ancient Layered Rocks on Mar
…
| Title |
Ancient Layered Rocks on Mars |
| Explanation |
Is this a picture of Mars or Earth? Oddly enough, it is a picture of Mars [ http://www.nineplanets.org/mars.html ]. What may appear to some as a terrestrial coastline [ http://antwrp.gsfc.nasa.gov/apod/ap971108.html ] is in fact a formation of ancient layered rocks [ http://science.nasa.gov/headlines/y2001/ast23jan_1.htm ] and wind-blown sand [ http://www.paccd.cc.ca.us/instadmn/physcidv/geol_dp/dndougla/SAND/SANDHP.htm ] on Mars [ http://antwrp.gsfc.nasa.gov/apod/mars.html ]. The above-pictured [ http://mars.jpl.nasa.gov/mgs/msss/camera/images/10_30_01_releases/schiaparelli/index.html ] region spans about three kilometers in Schiaparelli Crater [ http://www.solarviews.com/cap/mars/me04s341.htm ]. What created the layers of sediment [ http://webserver.cr.usgs.gov/sediment/conc.frame.html ] is still a topic of research. Viable hypotheses [ http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2000Sci...290.1927M ] include ancient epochs [ http://antwrp.gsfc.nasa.gov/apod/ap001205.html ] of deposit either from running water or wind-blown sand. Winds [ http://antwrp.gsfc.nasa.gov/apod/ap990112.html ] and sandstorms [ http://antwrp.gsfc.nasa.gov/apod/ap011017.html ] have smoothed and eroded [ http://www.uwgb.edu/dutchs/202slide/windslid.htm ] the structures more recently. The "water" that appears near the bottom is actually dark colored sand. The image was taken with the Mars Global Surveyor spacecraft [ http://mars.jpl.nasa.gov/mgs/overvu/overview.html ] that has now returned over 100,000 images [ http://www.msss.com/mars_images/moc/100000th_image/index.html ]. |
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Carving Ma'adim Vallis
| Title |
Carving Ma'adim Vallis |
| Explanation |
Just as erosion from the Colorado River carved the Grand Canyon [ http://www.aqd.nps.gov/grd/parks/grca/ ] on Earth, a river of flood water may have carved Ma'adim Vallis, one of the largest canyons on Mars [ http://antwrp.gsfc.nasa.gov/apod/ap970627.html ]. Researchers have presented strong evidence [ http://www.nasm.edu/nasm/pa/nasmnews/pr/research/ 062002.htm ] for such a scenario [ http://www.sciencemag.org/cgi/content/short/296/5576/2209 ] based on elevation data recorded by the MOLA [ http://ltpwww.gsfc.nasa.gov/tharsis/mola.html ] (Mars Orbiter Laser Altimeter) experiment on the Mars Global Surveyor [ http://mars.jpl.nasa.gov/mgs/ ] spacecraft. This false-color, detailed, topographical [ http://antwrp.gsfc.nasa.gov/apod/ap010628.html ] map of MOLA data shows in blue the area of an enormous complex of lakes that are thought [ http://www.nasm.si.edu/ceps/research/mars/irwin_lakes.htm ] to have existed over three and a half billion years ago in the southern highlands of Mars. As the largest lake spilled over the low point in its boundary a torrential flood would have moved north, along the direction indicated by the arrow, carving the sinuous Ma'adim Vallis. At the north end of Ma'adim Vallis, the flood waters would have poured into large, round Gusev Crater [ http://www.psrd.hawaii.edu/Sept98/GusevMars.html ]. Since standing bodies of surface water are thought to be favorable for ancient martian microbial life [ http://science.nasa.gov/newhome/headlines/ ast11jun99_1.htm ], Gusev Crater has been suggested as a landing site for future Mars missions [ http://mars.jpl.nasa.gov/missions/future/ express.html ]. |
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Ancient Volcanos of Mars
| Title |
Ancient Volcanos of Mars |
| Explanation |
Findings of ancient martian microbial fossils [ http://ares.jsc.nasa.gov/astrobiology/biomarkers/ recentnews.html ] in meteorites and liquid water related [ http://science.msfc.nasa.gov/headlines/y2000/ ast29jun_1m.htm ] features on Mars' surface [ http://unisci.com/stories/20012/0402013.htm ] are currently controversial issues. But one thing long established by space-based observations of the Red Planet [ http://mars.jpl.nasa.gov/ ] is the presence of volcanos, as Mars supports some of the largest volcanos [ http://www.msss.com/http/ps/volcanoes.html ] in the solar system. This synthetic color picture recorded in March [ http://www.msss.com/mars_images/moc/news2002/ceraunius/ index.html ] by the Mars Global Surveyor spacecraft shows two of them, Ceraunius Tholus (leftmost) and Uranius Tholus. Found north of the Tharsis [ http://antwrp.gsfc.nasa.gov/apod/ap990618.html ] region of truly large martian volcanos [ http://antwrp.gsfc.nasa.gov/apod/ap000529.html ], these are actually two relatively small volcanos, Ceraunius Tholus being only about the size of the Big Island of Hawaii [ http://antwrp.gsfc.nasa.gov/apod/ap020425.html ] on planet Earth. Impact craters which overlay the volcanic martian terrain [ http://themis.la.asu.edu/latest.html ] indicate that these volcanos are [ http://www.solarviews.com/eng/marsvolc.htm ] themselves ancient and inactive. North is to the right and the scene is illuminated by sunlight from the top left. A light region of dust deposited by recent global dust storms [ http://antwrp.gsfc.nasa.gov/apod/ap011017.html ] lies on the lower left flank of Ceraunius Tholus, whose summit crater is about 25 kilometers across. |
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A Dust Devil on Mars
| Title |
A Dust Devil on Mars |
| Explanation |
Does the surface of Mars [ http://www.nineplanets.org/mars.html ] change? When inspecting yearly images of the Martian surface [ http://antwrp.gsfc.nasa.gov/apod/ap020827.html ] taken by the robot spacecraft Mars Global Surveyor [ http://mars.jpl.nasa.gov/mgs/overvu/overview.html ] currently orbiting Mars [ http://antwrp.gsfc.nasa.gov/apod/mars.html ], sometimes new dark trails [ http://antwrp.gsfc.nasa.gov/apod/ap000317.html ] are visible. Although originally a mystery, the culprit is now usually known to be a dust devil [ http://mars.jpl.nasa.gov/gallery/duststorms/ ], a huge swirling gas-cloud with similarities to a terrestrial tornado. Pictured above [ http://www.msss.com/mars_images/moc/8_2002_releases/dustdevil/ ], a recent image has not only captured a new dark trail but the actual dust devil [ http://www.gi.alaska.edu/ScienceForum/ASF2/227.html ] itself climbing a crater wall [ http://antwrp.gsfc.nasa.gov/apod/ap000626.html ]. Dust devils [ http://www.aspsky.org/mercury/mercury/0002/carr1.html ] are created when Martian air [ http://www.pbs.org/saf/1109/features/mars.htm ] is heated by a warm surface and begins to spin as it rises. Dust devils [ http://nssdc.gsfc.nasa.gov/planetary/marspath/dustdevil.html ] can stretch 8 kilometers high but usually last only a few minutes. |
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Rectangular Ridges on Mars
| Title |
Rectangular Ridges on Mars |
| Explanation |
What could cause rectangular ridges on Mars? As data flows in from the two [ http://mars.jpl.nasa.gov/mgs/overvu/overview.html ] spacecraft [ http://mars.jpl.nasa.gov/odyssey/mission/index.html ] currently orbiting Mars [ http://www.nineplanets.org/mars.html ], surface structures are seen that are not immediately understood. These structures pose puzzles that planetary geologists are eager to solve, as they might provide clues to past processes that have shaped Mars [ http://antwrp.gsfc.nasa.gov/apod/ap010628.html ] over billions of years. On the right of the above image [ http://mars.jpl.nasa.gov/mgs/msss/camera/images/8_2002_releases/incacity/index.html ] is an unusual array of ridges first spotted in Mariner 9 [ http://nssdc.gsfc.nasa.gov/nmc/tmp/1971-051A.html ] data in 1972. A ridge wall runs for about 5 kilometers [ http://vulcan.wr.usgs.gov/Miscellaneous/ConversionTables/conversion_table.html ]. Two competing progenitor theories include hardened sand dunes [ http://antwrp.gsfc.nasa.gov/apod/ap010226.html ] and once-molten rock that seeped through surface cracks and cooled. Dubbed "Inca City" for their resemblance to stone walls of an ancient Earth civilization [ http://emuseum.mnsu.edu/prehistory/latinamerica/south/cultures/inca.html ], the new Mars Global Surveyor [ http://mars.jpl.nasa.gov/mgs/overvu/overview.html ] images now show them to be part of a larger circular pattern, indicating an origin possibly related to the impact crater [ http://antwrp.gsfc.nasa.gov/apod/ap001213.html ]. (Non-natural origin hypotheses are not invoked by conservative scientists unless clear indications exist that natural processes could not work.) |
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Gullies on Mars
| Title |
Gullies on Mars |
| Explanation |
The Gullies of Mars [ http://www.literature.org/authors/burroughs-edgar-rice/ the-gods-of-mars/foreword.html ] would probably not have been sensational [ http://antwrp.gsfc.nasa.gov/apod/ap001114.html ] enough for the title of a vintage Edgar Rice Burroughs [ http://www.tarzan.org/ official_biography_part1.html ] story about the Red Planet. But it would get the attention [ http://nssdc.gsfc.nasa.gov/planetary/news/ mars_water_pr_20000622.html ] of planetary scientists today. First identified in [ http://antwrp.gsfc.nasa.gov/apod/ap000623.html ] high resolution images of Mars recorded by the orbiting Mars Global Surveyor spacecraft, the gullies are interpreted as startling evidence that liquid water [ http://www.earthsky.com/Features/News/ 0623mars-water.html ] flowed across the martian surface in geologically recent times. Similar channels on Earth [ http://www.marsonearth.org/ ] are formed by flowing water, but on Mars [ http://antwrp.gsfc.nasa.gov/apod/ap970627.html ] the temperature is normally too cold and the atmosphere too thin to sustain liquid water. Still, it is thought possible that water did burst out from underground layers and remain liquid long enough [ http://science.nasa.gov/headlines/y2000/ ast22jun_2.htm ] to erode the gullies, while alternative explanations [ http://solarsystem.nasa.gov/whatsnew/ pr/010330A.html ] suggest the erosion was produced by a flowing jumble of solid and gaseous carbon dioxide. Spanning a few kilometers along the wall of an impact crater this high resolution image [ http://www.msss.com/mars_images/moc/e7_e12_captioned_rel/ index.html ] from Mars Global Surveyor [ http://mars.jpl.nasa.gov/mgs/ ] shows typical martian gullies near the top of the crater wall giving way to sand dunes toward the crater floor. Whitish frost is visible near the top and on the dark sand dunes below. The muted colors were synthesized from wide angle image data. |
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The Shadow of Phobos
| Title |
The Shadow of Phobos |
| Explanation |
Hurtling through space [ http://antwrp.gsfc.nasa.gov/apod/ap990313.html ] above the Red Planet, potato-shaped Phobos [ http://www.seds.org/nineplanets/nineplanets/ phobos.html ] completes an orbit of Mars in less than eight hours. In fact, since its orbital period is shorter than the planet's [ http://nssdc.gsfc.nasa.gov/planetary/factsheet/ marsfact.html ] rotation period, Mars-based observers [ http://www.literature.org/authors/burroughs-edgar-rice/ the-warlord-of-mars/ ] see Phobos rise in the west and set in the east - traveling from horizon to horizon in about 5 1/2 hours. These three images [ http://www.msss.com/mars_images/moc/11_1_99_phobos/ index.html ] from the Mars Global Surveyor (MGS) spacecraft [ http://ic-www.arc.nasa.gov/ic/projects/bayes-group/ Atlas/Mars/VSC/views/entrance/entrance.html ] record the oval shadow [ http://antwrp.gsfc.nasa.gov/apod/ap990830.html ] of Phobos racing over western Xanthe Terra on August 26, 1999. The area imaged is about 250 kilometers across and is seen in panels from left to right as red filter, blue filter, and combined color composite views from the MGS wide-angle camera system. The three dark spots most easily seen in the red filter image are likely small fields of dark sand dunes [ http://antwrp.gsfc.nasa.gov/apod/ap010815.html ] on crater floors. Standing in the shadow of Phobos [ http://nssdc.gsfc.nasa.gov/planetary/mars/mars_crew.html ], you would see the Martian version [ http://humbabe.arc.nasa.gov/mgcm/fun/pop.html ] of a solar eclipse! |
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The Earth and Moon from Mars
| Title |
The Earth and Moon from Mars |
| Explanation |
What does Earth [ http://antwrp.gsfc.nasa.gov/apod/ap010204.html ] look like from Mars [ http://www.nineplanets.org/mars.html ]? The first image [ http://photojournal.jpl.nasa.gov/catalog/PIA04531 ] of Earth from the red planet was captured earlier this month by the camera onboard the Mars Global Surveyor spacecraft [ http://antwrp.gsfc.nasa.gov/apod/ap030526.html http://mars.jpl.nasa.gov/mgs/overvu/overview.html ] currently orbiting Mars. Features visible on Earth include the Pacific Ocean [ http://www.cia.gov/cia/publications/factbook/geos/zn.html ], clouds [ http://seaborg.nmu.edu/Clouds/types.html ], much of South America [ http://www.infoplease.com/atlas/southamerica.html ], and part of North America [ http://www.infoplease.com/atlas/northamerica.html ]. Earth's Moon [ http://antwrp.gsfc.nasa.gov/apod/ap020316.html ] is visible on the upper right, with the crater Tycho [ http://antwrp.gsfc.nasa.gov/apod/ap010809.html ] brightening the lower part. Previously, Earth has been imaged from the Moon [ http://antwrp.gsfc.nasa.gov/apod/ap000701.html ] and spacecraft [ http://antwrp.gsfc.nasa.gov/apod/ap011015.html ] across [ http://antwrp.gsfc.nasa.gov/apod/ap020127.html ] the [ http://antwrp.gsfc.nasa.gov/apod/ap000325.html ] Solar [ http://antwrp.gsfc.nasa.gov/apod/ap980904.html ] System [ http://setiathome.ssl.berkeley.edu/pale_blue_dot.html ]. |
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