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Band of Rubble
Title Band of Rubble
Description This artist's animation illustrates a massive asteroid belt in orbit around a star the same age and size as our Sun. Evidence for this possible belt was discovered by NASA's Spitzer Space Telescope when it spotted warm dust around the star, presumably from asteroids smashing together. The view starts from outside the belt, where planets like the one shown here might possibly reside, then moves into to the dusty belt itself. A collision between two asteroids is depicted near the end of the movie. Collisions like this replenish the dust in the asteroid belt, making it detectable to Spitzer. The alien belt circles a faint, nearby star called HD 69830 located 41 light-years away in the constellation Puppis. Compared to our own solar system's asteroid belt, this one is larger and closer to its star -- it is 25 times as massive, and lies just inside an orbit equivalent to that of Venus. Our asteroid belt circles between the orbits of Mars and Jupiter. Because Jupiter acts as an outer wall to our asteroid belt, shepherding its debris into a series of bands, it is possible that an unseen planet is likewise marshalling this belt's rubble. Previous observations using the radial velocity technique did not locate any large gas giant planets, indicating that any planets present in this system would have to be the size of Saturn or smaller. Asteroids are chunks of rock from "failed" planets, which never managed to coalesce into full-sized planets. Asteroid belts can be thought of as construction sites that accompany the building of rocky planets.
It's a Rocky World
Title It's a Rocky World
Description This artist's concept show a massive asteroid belt in orbit around a star the same age and size as our Sun. Evidence for this possible belt was discovered by NASA's Spitzer Space Telescope when it spotted warm dust around the star, presumably from asteroids smashing together. The view is from outside the belt, where planets like the one shown in the foreground, might possibly reside. A collision between two asteroids is depicted to the right. Collisions like this replenish the dust in the asteroid belt, making it detectable to Spitzer. The alien belt circles a faint, nearby star called HD 69830 located 41 light-years away in the constellation Puppis. Compared to our own solar system's asteroid belt, this one is larger and closer to its star -- it is 25 times as massive, and lies just inside an orbit equivalent to that of Venus. Our asteroid belt circles between the orbits of Mars and Jupiter. Because Jupiter acts as an outer wall to our asteroid belt, shepherding its debris into a series of bands, it is possible that an unseen planet is likewise marshalling this belt's rubble. Previous observations using the radial velocity technique did not locate any large gas giant planets, indicating that any planets present in this system would have to be the size of Saturn or smaller. Asteroids are chunks of rock from "failed" planets, which never managed to coalesce into full-sized planets. Asteroid belts can be thought of as construction sites that accompany the building of rocky planets.
Measurements of the Martian …
PIA01340
Sol (our sun)
Thermal Emission Spectromete …
Title Measurements of the Martian Winds for Three Seasons
Original Caption Released with Image Observations (from the Thermal Emission Spectrometer, or TES, instrument)covering one half martian year allow us to follow the development of the northern winter polar vortex. This high speed west wind builds up from fall ("early October" in a calendar seasonally equivalent to the terrestrial calendar) to maximum strength in winter ("late December"). As spring approaches ("late March"), it gradually declines. At maximum strength its winds exceed 160 m/s (360 miles per hour). It also acts as an effective barrier to the northward transport of atmospheric dust, during its most active phase, only condensates (water and CO2 ices) were observed in its core. Detailed study of this effect is important to determine the accumulation of deposits on the permanent polar cap. The TES instrument was built by Santa Barbara Remote Sensing and is operated by Philip R. Christensen, of Arizona State University, Tempe, AZ. The MGS mission is managed for NASA by the Jet Propulsion Laboratory, Pasadena CA.
Auqakuh Valles
PIA03824
Sol (our sun)
Thermal Emission Imaging Sys …
Title Auqakuh Valles
Original Caption Released with Image (Released 7 June 2002) The Science This ancient sinuous river channel, located near 30° N, 299° W (61° E), was likely carved by water early in Mars history. Auqakuh Valles cuts through a remarkable series of rock layers that were deposited and then subsequently eroded. This change from conditions favoring deposition to those favoring erosion indicates that the environment of this region has changed significantly over time. In addition, the different rock layers seen in this image vary in hardness, with some being relatively soft and easily eroded, whereas others are harder and resistant. These differences imply that these layers vary in their composition, physical properties, and/or degree of cementation, and again suggest that major changes have occurred during the history of this region. Similar differences occur throughout the southwest U.S., where hard rock layers, such as the limestones and sandstones in the Grand Canyon, form resistant cliffs, whereas softer mudstones are easily eroded to form broad slopes. The Martian layers, such as the smooth, dark-toned mesas visible in numerous places to the right (east) of the channel, were once continuous across the region. As these layers have eroded, they have produced a wide array of textures, from smooth surfaces, to knobby terrains, to the unusual lobate patterns seen in the upper right of the image. The most recent activity in the region appears to be the formation of mega-ripples by the wind. These ripples, spaced approximately 75 m apart, form perpendicular to the wind direction, and can be seen following the pattern of the channel floor as it curves through this region. This pattern shows that even this relatively small channel, which varies in width from about 500 to 750 m throughout this image, acts to funnel the wind down the channel. The Story Auqakuh Vallis, an ancient river channel that winds its way down the center of this image, is the "fossil" remains of an earlier, probably more watery time in Martian history. Now, you might think that Auqakuh has something to do with Aqua, the Latin word for water. Instead, Auqakuh is the word for Mars in the Quechuan language of the Incan Empire that once stretched across vast portions of South America. This Inca-honoring river channel cuts through a remarkable series of rock layers that expose a history of climate change in the region. The coarse, rugged, and wildly textured terrain was created as rock layers were first deposited, then eroded over time. Some of the rock layers are soft and easily eroded, while others are clearly harder and more resistant. From these differences, geologists can tell that the layers are made up of different materials, have different physical characteristics, and are either loosely or strongly cemented together. That suggests major environmental changes over time as well, since different kinds of rocks form under different conditions. Similar differences in rock layers occur throughout the Southwest of the, United States. The next time you're visiting the Grand Canyon or hiking in similar terrain, notice where hard rock layers, such as limestones and sandstones, form resistant cliffs, whereas softer mudstones are easily eroded to form broad slopes along the canyon. Just in case the river channel in the above image looks more like a raised vein rather than a hollowed out channel, try looking at the half-circle depression on the left-hand side of the image, about a third of the way up. The bright features on the upper half streak down toward the bottom of the bowl. Once you focus on this for a while, your brain figures out that the channel must be depressed as well. Now that you can see that the channel cuts into the surface, click on the image for a closer look at the bottom of the channel. Mega-ripples about 82 yards apart line the channel floor as it curves through the region. This pattern shows that even this relatively small channel, which varies from about one-third to a half of a mile in width, funnels the wind down its curving length, creating perpendicular piles of waving texture on the channel's floor. East of the channel, smooth, dark-toned mesas are visible, providing a scant reminder that they were once continuous across the region. As these layers have eroded, they've produced a wide array of textures, from smooth surfaces, to knobby terrains, to the unusual curved, lobe-like patterns seen in the upper right of the image.
Auqakuh Valles
PIA03824
Sol (our sun)
Thermal Emission Imaging Sys …
Title Auqakuh Valles
Original Caption Released with Image (Released 7 June 2002) The Science This ancient sinuous river channel, located near 30° N, 299° W (61° E), was likely carved by water early in Mars history. Auqakuh Valles cuts through a remarkable series of rock layers that were deposited and then subsequently eroded. This change from conditions favoring deposition to those favoring erosion indicates that the environment of this region has changed significantly over time. In addition, the different rock layers seen in this image vary in hardness, with some being relatively soft and easily eroded, whereas others are harder and resistant. These differences imply that these layers vary in their composition, physical properties, and/or degree of cementation, and again suggest that major changes have occurred during the history of this region. Similar differences occur throughout the southwest U.S., where hard rock layers, such as the limestones and sandstones in the Grand Canyon, form resistant cliffs, whereas softer mudstones are easily eroded to form broad slopes. The Martian layers, such as the smooth, dark-toned mesas visible in numerous places to the right (east) of the channel, were once continuous across the region. As these layers have eroded, they have produced a wide array of textures, from smooth surfaces, to knobby terrains, to the unusual lobate patterns seen in the upper right of the image. The most recent activity in the region appears to be the formation of mega-ripples by the wind. These ripples, spaced approximately 75 m apart, form perpendicular to the wind direction, and can be seen following the pattern of the channel floor as it curves through this region. This pattern shows that even this relatively small channel, which varies in width from about 500 to 750 m throughout this image, acts to funnel the wind down the channel. The Story Auqakuh Vallis, an ancient river channel that winds its way down the center of this image, is the "fossil" remains of an earlier, probably more watery time in Martian history. Now, you might think that Auqakuh has something to do with Aqua, the Latin word for water. Instead, Auqakuh is the word for Mars in the Quechuan language of the Incan Empire that once stretched across vast portions of South America. This Inca-honoring river channel cuts through a remarkable series of rock layers that expose a history of climate change in the region. The coarse, rugged, and wildly textured terrain was created as rock layers were first deposited, then eroded over time. Some of the rock layers are soft and easily eroded, while others are clearly harder and more resistant. From these differences, geologists can tell that the layers are made up of different materials, have different physical characteristics, and are either loosely or strongly cemented together. That suggests major environmental changes over time as well, since different kinds of rocks form under different conditions. Similar differences in rock layers occur throughout the Southwest of the, United States. The next time you're visiting the Grand Canyon or hiking in similar terrain, notice where hard rock layers, such as limestones and sandstones, form resistant cliffs, whereas softer mudstones are easily eroded to form broad slopes along the canyon. Just in case the river channel in the above image looks more like a raised vein rather than a hollowed out channel, try looking at the half-circle depression on the left-hand side of the image, about a third of the way up. The bright features on the upper half streak down toward the bottom of the bowl. Once you focus on this for a while, your brain figures out that the channel must be depressed as well. Now that you can see that the channel cuts into the surface, click on the image for a closer look at the bottom of the channel. Mega-ripples about 82 yards apart line the channel floor as it curves through the region. This pattern shows that even this relatively small channel, which varies from about one-third to a half of a mile in width, funnels the wind down its curving length, creating perpendicular piles of waving texture on the channel's floor. East of the channel, smooth, dark-toned mesas are visible, providing a scant reminder that they were once continuous across the region. As these layers have eroded, they've produced a wide array of textures, from smooth surfaces, to knobby terrains, to the unusual curved, lobe-like patterns seen in the upper right of the image.
Dust Devil Tracks
PIA03791
Sol (our sun)
Thermal Emission Imaging Sys …
Title Dust Devil Tracks
Original Caption Released with Image (Released 8 May 2002) The Science This image, centered near 50.0 S and 17.7 W displays dust devil tracks on the surface. Most of the lighter portions of the image likely have a thin veneer of dust settled on the surface. As a dust devil passes over the surface, it acts as a vacuum and picks up the dust, leaving the darker substrate exposed. In this image there is a general trend of many of the tracks running from east to west or west to east, indicating the general wind direction. There is often no general trend present in dust devil tracks seen in other images. The track patterns are quite ephemeral and can completely change or even disappear over the course of a few months. Dust devils are one of the mechanisms that Mars uses to constantly pump dust into the ubiquitously dusty atmosphere. This atmospheric dust is one of the main driving forces of the present Martian climate. The Story Vrrrrooooooooom. Think of a tornado, the cartoon Tasmanian devil, or any number of vacuum commercials that powerfully suck up swirls of dust and dirt. That's pretty much what it's like on the surface of Mars a lot of the time. Whirlpools of wind called
Band of Rubble
PIA07854
Title Band of Rubble
Original Caption Released with Image This artist's animation illustrates a massive asteroid belt in orbit around a star the same age and size as our Sun. Evidence for this possible belt was discovered by NASA's Spitzer Space Telescope when it spotted warm dust around the star, presumably from asteroids smashing together. The view starts from outside the belt, where planets like the one shown here might possibly reside, then moves into to the dusty belt itself. A collision between two asteroids is depicted near the end of the movie. Collisions like this replenish the dust in the asteroid belt, making it detectable to Spitzer. The alien belt circles a faint, nearby star called HD 69830 located 41 light-years away in the constellation Puppis. Compared to our own solar system's asteroid belt, this one is larger and closer to its star - it is 25 times as massive, and lies just inside an orbit equivalent to that of Venus. Our asteroid belt circles between the orbits of Mars and Jupiter. Because Jupiter acts as an outer wall to our asteroid belt, shepherding its debris into a series of bands, it is possible that an unseen planet is likewise marshalling this belt's rubble. Previous observations using the radial velocity technique did not locate any large gas giant planets, indicating that any planets present in this system would have to be the size of Saturn or smaller. Asteroids are chunks of rock from "failed" planets, which never managed to coalesce into full-sized planets. Asteroid belts can be thought of as construction sites that accompany the building of rocky planets.
Mars Researchers Rendezvous …
PIA03714
Sol (our sun)
Multi-angle Imaging SpectroR …
Title Mars Researchers Rendezvous on Remote Arctic Island
Original Caption Released with Image Devon Island is situated in an isolated part of Canada's Nunavut Territory, and is usually considered to be the largest uninhabited island in the world. However, each summer since 1999, researchers from NASA's Haughton-Mars Project and the Mars Society reside at this "polar desert" location to study the geologic and environmental characteristics of a site which is considered to be an excellent "Mars analog": a terrestrial location wherein specific conditions approximate environmental features reported on Mars. Base camps established amidst the rocks and rubble surrounding the Haughton impact crater enable researchers to conduct surveys designed to test the habitat, equipment and technology that may be deployed during a human mission to Mars. One of the many objectives of the project scientists is to understand the ice formations around the Haughton area, in the hopes that this might ultimately assist with the recognition of areas where ice can be found at shallow depth on Mars. These images of Devon Island from NASA's Multi-angle Imaging SpectroRadiometer (MISR) instrument provide contrasting views of the spectral and angular reflectance "signatures" of different surfaces within the region. The top panel is a natural color view created with data from the red, green and blue-bands of MISR's nadir (vertical-viewing) camera. The bottom panel is a false-color multiangular composite of the same area, utilizing red band data from MISR's 60-degree backward, nadir, and 60-degree forward-viewing cameras, displayed as red, green and blue, respectively. In this representation, colors highlight textural properties of elements within the scene, with blue tones indicating smooth surfaces (which preferentially forward scatter sunlight) and red hues indicating rougher surfaces (which preferentially backscatter). The angular reflectance "signature" of low clouds causes them to appear purple, and this visualization provides a unique way of distinguishing clouds from snow and ice. The data were captured on June 28, 2001, during the early part of the arctic summer, when sea ice becomes thinner and begins to move depending upon localized currents and winds. In winter the entire region is locked with several meters of nearly motionless sea ice, which acts as a thermodynamic barrier to the loss of heat from the comparatively warm ocean to the colder atmosphere. Summer melting of sea ice can be observed at the two large, dark regions of open water, one is present in the Jones Sound (near the top to the left of center), and another appears in the Wellington Channel (left-hand edge). A large crack caused by tidal heaving has broken the ice cover over the Parry Channel (lower right-hand corner). A substantial ice cap permanently occupies the easternmost third of the island (upper right). Surface features such as dendritic meltwater channels incised into the island's surface are apparent. The Haughton-Mars project site is located slightly to the left and above image, center, in an area which appears with relatively little surface ice, near the island's inner "elbow." The images were acquired during Terra orbit 8132 and cover an area of about 334 kilometers x 229 kilometers. They utilize data from blocks 27 to 31 within World Reference System-2 path 42. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.
Candor Chasma
PIA03838
Sol (our sun)
Thermal Emission Imaging Sys …
Title Candor Chasma
Original Caption Released with Image (Released 27 June 2002) The Science This THEMIS visible image shows the effects of erosion on a beautiful sequence of dramatically layered rocks within Candor Chasma, which is part of the Valles Marineris. These layers were initially deposited within Candor, and have subsequently been eroded by a variety of processes, including wind and downslope motion due to gravity. The effect of erosion is manifest differently in the different layers and at different locations within the layered material. For example, the upper portion of the Candor deposit seen in the lower one-third of the image appears more intact, whereas downslope there is pronounced fluting to create produced "spur and gully" slopes. Relatively dark materials are seen throughout the image and appear to mantle select areas of the layered deposits. When seen in other areas by THEMIS, and at higher resolution by the Mars Global Surveyor camera, these dark materials often form sand dunes. The dark mantling material in Candor is likely dark sand as well. Several particularly dark patches can be seen near the left (western) edge of the image, approximately one quarter of the way up from the bottom of the image. Very few impact craters of any size can be seen in this image, indicating that the erosion and transport of material is occurring at a relatively rapid rate, so that any craters that form are rapidly buried or eroded. The Story The smooth, triangular shape near the center of this image is the plateau of a canyon, with walls that dramatically descend on either side. This canyon is named Chasma, which means "blaze" or "white" in Latin. The lighter, brighter material of the southern canyon wall displays erosional streaks that almost do happen to look like a white blaze. Toward the bottom left of the image, you can see how the relatively brighter material from the top has been carried down to the bottom. Notice that the upper, grayer part of the southern canyon walls don't seem to have the same erosional flutes as the brighter material just below it. By looking at such differences on the same canyon wall, geologists can begin to understand the kinds of materials that make up each layer of the canyon wall, and how resistant each is to erosion. No matter what part of the canyon you look at, erosion has created the beautiful sequence of layered rocks within Candor. Sometimes it's the wind that acts, and sometimes gravity, which pulls material from the upper parts of the canyon downslope. Be sure to click on the above image for a close-up view of all of the subtle layers and ripples. Look also for some dark, almost black patches (bottom left, about a quarter of the way up). These dark splotches are most likely made of sand. In fact, much of the darker areas seen in this image are probably made of sand. The sand often forms in dunes, as both THEMIS and the higher resolution camera on Mars Global Surveyor, Odyssey's sister orbiter, have shown. With all of the wind and downslope erosion,, , this area is fairly active geologically. You can tell because there are very few impact craters of any size to be seen. That means material is being transported at a rate that's rapid enough to bury or erode any craters that do form. Candor Chasma is part of Valles Marineris, the large canyon system that slices across a large part of the red planet. If Valles Marineris were located on Earth, it would stretch all the way from the west coast to the east coast of the United States.
Candor Chasma
PIA03838
Sol (our sun)
Thermal Emission Imaging Sys …
Title Candor Chasma
Original Caption Released with Image (Released 27 June 2002) The Science This THEMIS visible image shows the effects of erosion on a beautiful sequence of dramatically layered rocks within Candor Chasma, which is part of the Valles Marineris. These layers were initially deposited within Candor, and have subsequently been eroded by a variety of processes, including wind and downslope motion due to gravity. The effect of erosion is manifest differently in the different layers and at different locations within the layered material. For example, the upper portion of the Candor deposit seen in the lower one-third of the image appears more intact, whereas downslope there is pronounced fluting to create produced "spur and gully" slopes. Relatively dark materials are seen throughout the image and appear to mantle select areas of the layered deposits. When seen in other areas by THEMIS, and at higher resolution by the Mars Global Surveyor camera, these dark materials often form sand dunes. The dark mantling material in Candor is likely dark sand as well. Several particularly dark patches can be seen near the left (western) edge of the image, approximately one quarter of the way up from the bottom of the image. Very few impact craters of any size can be seen in this image, indicating that the erosion and transport of material is occurring at a relatively rapid rate, so that any craters that form are rapidly buried or eroded. The Story The smooth, triangular shape near the center of this image is the plateau of a canyon, with walls that dramatically descend on either side. This canyon is named Chasma, which means "blaze" or "white" in Latin. The lighter, brighter material of the southern canyon wall displays erosional streaks that almost do happen to look like a white blaze. Toward the bottom left of the image, you can see how the relatively brighter material from the top has been carried down to the bottom. Notice that the upper, grayer part of the southern canyon walls don't seem to have the same erosional flutes as the brighter material just below it. By looking at such differences on the same canyon wall, geologists can begin to understand the kinds of materials that make up each layer of the canyon wall, and how resistant each is to erosion. No matter what part of the canyon you look at, erosion has created the beautiful sequence of layered rocks within Candor. Sometimes it's the wind that acts, and sometimes gravity, which pulls material from the upper parts of the canyon downslope. Be sure to click on the above image for a close-up view of all of the subtle layers and ripples. Look also for some dark, almost black patches (bottom left, about a quarter of the way up). These dark splotches are most likely made of sand. In fact, much of the darker areas seen in this image are probably made of sand. The sand often forms in dunes, as both THEMIS and the higher resolution camera on Mars Global Surveyor, Odyssey's sister orbiter, have shown. With all of the wind and downslope erosion,, , this area is fairly active geologically. You can tell because there are very few impact craters of any size to be seen. That means material is being transported at a rate that's rapid enough to bury or erode any craters that do form. Candor Chasma is part of Valles Marineris, the large canyon system that slices across a large part of the red planet. If Valles Marineris were located on Earth, it would stretch all the way from the west coast to the east coast of the United States.
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