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Cerberus Wind Streaks
PIA03789
Sol (our sun)
Thermal Emission Imaging Sys
…
| Title |
Cerberus Wind Streaks |
| Original Caption Released with Image |
(Released 6 May 2002) The Science Cerberus is a dark region on Mars that has shrunk down from a continuous length of about 1000 km to roughly three discontinuous spots a few 100 kms in length in less than 20 years. There are two competing processes at work in the Cerberus region that produce the bright and dark features seen in this THEMIS image. Bright dust settles out of the atmosphere, especially after global dust storms, depositing a layer just thick enough to brighten the dark surfaces. Deposition occurs preferentially in the low wind "shadow zones" within craters and downwind of crater rims, producing the bright streaks. The direction of the streaks clearly indicates that the dominant winds come from the northeast. Dust deposition would completely blot out the dark areas if it were not for the action of wind-blown sand grains scouring the surface and lifting the dust back into the atmosphere. Again, the shadow zones are protected from the blowing sand, preserving the bright layer of dust. Also visible in this image are lava flow features extending from the flanks of the huge Elysium volcanoes to the northwest. Two shallow channels and a raised flow lobe are just barely discernable. The lava channel in the middle of the image crosses the boundary of the bright and dark surfaces without any obvious change in its morphology. This demonstrates that the bright dust layer is very thin in this location, perhaps as little as a few millimeters. The Story Mars is an ever-changing land of spectacular contrasts. This THEMIS image shows the Cerberus region of Mars, a dark area located near the Elysium volcanoes and fittingly named after the three-headed, dragon-tailed dog who guards the door of the underworld. Two opposing processes are at work here: a thin layer of dust falling from the atmosphere and/or dust storms creating brighter surface areas (e.g. the top left portion of this image) and dust being scoured away by the action of the Martian wind disturbing the sand grains and freeing the lighter dust to fly away once more (the darker portions of this image). There are, however, some darker areas that are somewhat shielded and protected from the wind that have yielded bright, dusty crater floors and wind streaks that trail out behind the craters. These wind streaks tell a story all their own as to the prevailing wind direction coming from the northeast. This, added to the fact that this dark region was once 1000 km in length and has dwindled to just a few isolated dark splotches of 100 kilometers in the past 20 years, help us to see that the Martian environment is still quite dynamic and capable of changing. Finally, this being a volcanic region, a lobe of a lava flow from the immense Elysium volcanoes to the northwest is visible stretching across the bottom one-quarter of the image. |
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Cerberus Wind Streaks
PIA03789
Sol (our sun)
Thermal Emission Imaging Sys
…
| Title |
Cerberus Wind Streaks |
| Original Caption Released with Image |
(Released 6 May 2002) The Science Cerberus is a dark region on Mars that has shrunk down from a continuous length of about 1000 km to roughly three discontinuous spots a few 100 kms in length in less than 20 years. There are two competing processes at work in the Cerberus region that produce the bright and dark features seen in this THEMIS image. Bright dust settles out of the atmosphere, especially after global dust storms, depositing a layer just thick enough to brighten the dark surfaces. Deposition occurs preferentially in the low wind "shadow zones" within craters and downwind of crater rims, producing the bright streaks. The direction of the streaks clearly indicates that the dominant winds come from the northeast. Dust deposition would completely blot out the dark areas if it were not for the action of wind-blown sand grains scouring the surface and lifting the dust back into the atmosphere. Again, the shadow zones are protected from the blowing sand, preserving the bright layer of dust. Also visible in this image are lava flow features extending from the flanks of the huge Elysium volcanoes to the northwest. Two shallow channels and a raised flow lobe are just barely discernable. The lava channel in the middle of the image crosses the boundary of the bright and dark surfaces without any obvious change in its morphology. This demonstrates that the bright dust layer is very thin in this location, perhaps as little as a few millimeters. The Story Mars is an ever-changing land of spectacular contrasts. This THEMIS image shows the Cerberus region of Mars, a dark area located near the Elysium volcanoes and fittingly named after the three-headed, dragon-tailed dog who guards the door of the underworld. Two opposing processes are at work here: a thin layer of dust falling from the atmosphere and/or dust storms creating brighter surface areas (e.g. the top left portion of this image) and dust being scoured away by the action of the Martian wind disturbing the sand grains and freeing the lighter dust to fly away once more (the darker portions of this image). There are, however, some darker areas that are somewhat shielded and protected from the wind that have yielded bright, dusty crater floors and wind streaks that trail out behind the craters. These wind streaks tell a story all their own as to the prevailing wind direction coming from the northeast. This, added to the fact that this dark region was once 1000 km in length and has dwindled to just a few isolated dark splotches of 100 kilometers in the past 20 years, help us to see that the Martian environment is still quite dynamic and capable of changing. Finally, this being a volcanic region, a lobe of a lava flow from the immense Elysium volcanoes to the northwest is visible stretching across the bottom one-quarter of the image. |
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Pavonis Mons
PIA03790
Sol (our sun)
Thermal Emission Imaging Sys
…
| Title |
Pavonis Mons |
| Original Caption Released with Image |
(Released 7 May 2002) The Science Four exceptionally large volcanoes in a region called Tharsis are unique to the western hemisphere of Mars. Three of the Tharsis volcanoes, Ascraeus Mons, Pavonis Mons, and Arsia Mons, are aligned along a NE - SW trend, with Pavonis in the middle, straddling the equator. Olympus Mons, the fourth Tharsis volcano and the largest in the solar system, is located NW of Pavonis Mons. At the top right of the image, the rim of the caldera of Pavonis Mons is just barely visible, with steep NE-facing cliffs formed by the collapse of a portion of the volcano's summit. At the southwest edge of the caldera, additional fractures are apparent and may someday collapse, making the summit caldera even larger. This image of Pavonis Mons also demonstrates some of the distinctive characteristics of the martian surface in the Tharsis region. Tharsis is very dusty, the dust covers everything like fresh snow, which is the reason why there is very little contrast in the surface materials as compared to other THEMIS images that show apparently bright and dark surfaces in the same picture. This dust cover makes it difficult to distinguish different geologic or geomorphic units in the area, and even the piles of lava flows that constructed this volcano are difficult to make out. Most of the craters on the volcano are small, a few tens of meters to kilometers in diameter, suggesting that this surface is a relatively young one on Mars (the older a surface is, the more and larger craters it has). In the lower third of the image, linear arrangements of small, round pits can be seen. These features are commonly called "pit chains" and most likely represent the collapse of lava tubes. Lava tubes are like a subway, allowing molten rock to move from place to place underground. A particularly large pit near the bottom center of the image looks a lot like a crater. However, the lack of degradation of the rim of this feature suggests that if it were an impact crater, it would be relatively young, and an ejecta blanket of debris should be visible. Because there is no apparent sign of an ejecta blanket, it is more likely that this and nearby similar features are simply the result of larger collapses. The Story Mars is Volcano Land, home to the largest volcanoes in the solar system. The small context image to the right shows a hole reminiscent of Darth Vader's Death Star, but it's really the sunken-in mouth of Pavonis Mons, one of three volcanoes that fall in a line across the Martian surface, almost like giant beads. You can see the very edge of this deep volcano hole at the uppermost righthand corner of the image. Deep fractures at the southwest edge of the caldera suggest that surrounding terrain might collapse, making the volcano depression even larger someday. Except for this darker hole, the landscape looks rather drab and uniform in color. No wonderful black-and-white contrasts of terrain appear here as they do in many other THEMIS images., That's because dust in this area covers everything like fresh snow, giving the surface a smooth and unvaried look. Unfortunately, that makes it really hard for scientists to understand what different kinds of geologic features are present and what the lava flows are like. Usually, you can tell something about when each lava layer happened . . . but that depends on being able to see how each of the layers flowed over and under one another. That's not apparent here. There are, however, some really cool features to study in this image. Deep, trenchlike tracings can be seen in the lower third of the image, as if a giant finger had scooped them out. So, how did they form? When a volcano erupts, lava flows in rivers, finding narrow channels that make easy pathways down the slopes. Gradually, the surface of the flow becomes crusted over, and the molten lava is confined to a tube of its own making. Lava tubes are a little like a subway, allowing molten rock to move from place to place underground. When the lava stops flowing from its source and the rest of it drains out, what's left? Long, hollow lava-tube caves that slope down the volcano. Sometimes these lava tubes collapse, forming "pit chains" like the long depressions seen here. While most of the round depressions in this image are craters, the large one near bottom center may fool you. Because it doesn't have a blanket of ejected material around it, its probably just a larger type "pit chain" collapse. The craters that we do see in this image have their own story to tell. Since most of them are small, they reveal that the exposed Martian surface is probably much younger than in other places. Older surfaces are typically pitted by larger craters. That?s because the planet was bombarded by much larger pieces of debris earlier in the formation of the solar system when more material was still "flying around." What this means is that the volcanic eruptions probably happened after the early stages of planetary bombardment, but not before all of the impacting material had a chance to make a lasting mark. |
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Pavonis Mons
PIA03790
Sol (our sun)
Thermal Emission Imaging Sys
…
| Title |
Pavonis Mons |
| Original Caption Released with Image |
(Released 7 May 2002) The Science Four exceptionally large volcanoes in a region called Tharsis are unique to the western hemisphere of Mars. Three of the Tharsis volcanoes, Ascraeus Mons, Pavonis Mons, and Arsia Mons, are aligned along a NE - SW trend, with Pavonis in the middle, straddling the equator. Olympus Mons, the fourth Tharsis volcano and the largest in the solar system, is located NW of Pavonis Mons. At the top right of the image, the rim of the caldera of Pavonis Mons is just barely visible, with steep NE-facing cliffs formed by the collapse of a portion of the volcano's summit. At the southwest edge of the caldera, additional fractures are apparent and may someday collapse, making the summit caldera even larger. This image of Pavonis Mons also demonstrates some of the distinctive characteristics of the martian surface in the Tharsis region. Tharsis is very dusty, the dust covers everything like fresh snow, which is the reason why there is very little contrast in the surface materials as compared to other THEMIS images that show apparently bright and dark surfaces in the same picture. This dust cover makes it difficult to distinguish different geologic or geomorphic units in the area, and even the piles of lava flows that constructed this volcano are difficult to make out. Most of the craters on the volcano are small, a few tens of meters to kilometers in diameter, suggesting that this surface is a relatively young one on Mars (the older a surface is, the more and larger craters it has). In the lower third of the image, linear arrangements of small, round pits can be seen. These features are commonly called "pit chains" and most likely represent the collapse of lava tubes. Lava tubes are like a subway, allowing molten rock to move from place to place underground. A particularly large pit near the bottom center of the image looks a lot like a crater. However, the lack of degradation of the rim of this feature suggests that if it were an impact crater, it would be relatively young, and an ejecta blanket of debris should be visible. Because there is no apparent sign of an ejecta blanket, it is more likely that this and nearby similar features are simply the result of larger collapses. The Story Mars is Volcano Land, home to the largest volcanoes in the solar system. The small context image to the right shows a hole reminiscent of Darth Vader's Death Star, but it's really the sunken-in mouth of Pavonis Mons, one of three volcanoes that fall in a line across the Martian surface, almost like giant beads. You can see the very edge of this deep volcano hole at the uppermost righthand corner of the image. Deep fractures at the southwest edge of the caldera suggest that surrounding terrain might collapse, making the volcano depression even larger someday. Except for this darker hole, the landscape looks rather drab and uniform in color. No wonderful black-and-white contrasts of terrain appear here as they do in many other THEMIS images., That's because dust in this area covers everything like fresh snow, giving the surface a smooth and unvaried look. Unfortunately, that makes it really hard for scientists to understand what different kinds of geologic features are present and what the lava flows are like. Usually, you can tell something about when each lava layer happened . . . but that depends on being able to see how each of the layers flowed over and under one another. That's not apparent here. There are, however, some really cool features to study in this image. Deep, trenchlike tracings can be seen in the lower third of the image, as if a giant finger had scooped them out. So, how did they form? When a volcano erupts, lava flows in rivers, finding narrow channels that make easy pathways down the slopes. Gradually, the surface of the flow becomes crusted over, and the molten lava is confined to a tube of its own making. Lava tubes are a little like a subway, allowing molten rock to move from place to place underground. When the lava stops flowing from its source and the rest of it drains out, what's left? Long, hollow lava-tube caves that slope down the volcano. Sometimes these lava tubes collapse, forming "pit chains" like the long depressions seen here. While most of the round depressions in this image are craters, the large one near bottom center may fool you. Because it doesn't have a blanket of ejected material around it, its probably just a larger type "pit chain" collapse. The craters that we do see in this image have their own story to tell. Since most of them are small, they reveal that the exposed Martian surface is probably much younger than in other places. Older surfaces are typically pitted by larger craters. That?s because the planet was bombarded by much larger pieces of debris earlier in the formation of the solar system when more material was still "flying around." What this means is that the volcanic eruptions probably happened after the early stages of planetary bombardment, but not before all of the impacting material had a chance to make a lasting mark. |
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Kasei Valles
PIA03792
Sol (our sun)
Thermal Emission Imaging Sys
…
| Title |
Kasei Valles |
| Original Caption Released with Image |
(Released 9 May 2002) Kasei Valles (Kasei is the Japanese word for Mars) is one of the largest outflow channels on Mars. Kasei Valles stretches some 2,000 km across the face of Mars and empties into the Chryse basin. This THEMIS image is of the northern branch of Kasei Valles and shows the channel floor and northern channel wall. The plateau surface located at the top of this image is more heavily cratered than the channel floor which indicates that the plateau is older than the channel floor. The wall of the plateau has spur and gully topography present. The floor of the channel has evidence of fluvial scour including a smaller inner channel. These features were probably carved out during waning stage flow. The probable causes of Martian floods are massive releases of subsurface water/ice due to possible subsurface volcanic activity. Martian outflow channels begin at point sources (chaotic terrain and box canyons) and then flow unconfined into a basin region. |
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Kasei Valles
PIA03792
Sol (our sun)
Thermal Emission Imaging Sys
…
| Title |
Kasei Valles |
| Original Caption Released with Image |
(Released 9 May 2002) Kasei Valles (Kasei is the Japanese word for Mars) is one of the largest outflow channels on Mars. Kasei Valles stretches some 2,000 km across the face of Mars and empties into the Chryse basin. This THEMIS image is of the northern branch of Kasei Valles and shows the channel floor and northern channel wall. The plateau surface located at the top of this image is more heavily cratered than the channel floor which indicates that the plateau is older than the channel floor. The wall of the plateau has spur and gully topography present. The floor of the channel has evidence of fluvial scour including a smaller inner channel. These features were probably carved out during waning stage flow. The probable causes of Martian floods are massive releases of subsurface water/ice due to possible subsurface volcanic activity. Martian outflow channels begin at point sources (chaotic terrain and box canyons) and then flow unconfined into a basin region. |
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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 |
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Degraded Crater Rim
PIA03788
Sol (our sun)
Thermal Emission Imaging Sys
…
| Title |
Degraded Crater Rim |
| Original Caption Released with Image |
(Released 3 May 2002) The Science The eastern rim of this unnamed crater in Southern Arabia Terra is very degraded (beaten up). This indicates that this crater is very ancient and has been subjected to erosion and subsequent bombardment from other impactors such as asteroids and comets. One of these later (younger) craters is seen in the upper right of this image superimposed upon the older crater rim material. Note that this smaller younger crater rim is sharper and more intact than the older crater rim. This region is also mantled with a blanket of dust. This dust mantle causes the underlying topography to take on a more subdued appearance. The Story When you think of Arabia, you probably think of hot deserts and a lot of profitable oil reserves. On Mars, however, Southern Arabia Terra is a cold place of cratered terrain. This almost frothy-looking image is the badly battered edge of an ancient crater, which has suffered both erosion and bombardment from asteroids, comets, or other impacting bodies over the long course of its existence. A blanket of dust has also settled over the region, which gives the otherwise rugged landscape a soft and more subdued appearance. The small, round crater (upper left) seems almost gemlike in its setting against the larger crater ring. But this companionship is no easy romance. Whatever formed the small crater clearly whammed into the larger crater rim at some point, obliterating part of its edge. You can tell the small crater was formed after the first and more devastating impact, because it is laid over the other larger crater. How much younger is the small one? Well, its rim is also much sharper and more intact, which gives a sense that it is probably far more youthful than the very degraded, ancient crater. |
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Degraded Crater Rim
PIA03788
Sol (our sun)
Thermal Emission Imaging Sys
…
| Title |
Degraded Crater Rim |
| Original Caption Released with Image |
(Released 3 May 2002) The Science The eastern rim of this unnamed crater in Southern Arabia Terra is very degraded (beaten up). This indicates that this crater is very ancient and has been subjected to erosion and subsequent bombardment from other impactors such as asteroids and comets. One of these later (younger) craters is seen in the upper right of this image superimposed upon the older crater rim material. Note that this smaller younger crater rim is sharper and more intact than the older crater rim. This region is also mantled with a blanket of dust. This dust mantle causes the underlying topography to take on a more subdued appearance. The Story When you think of Arabia, you probably think of hot deserts and a lot of profitable oil reserves. On Mars, however, Southern Arabia Terra is a cold place of cratered terrain. This almost frothy-looking image is the badly battered edge of an ancient crater, which has suffered both erosion and bombardment from asteroids, comets, or other impacting bodies over the long course of its existence. A blanket of dust has also settled over the region, which gives the otherwise rugged landscape a soft and more subdued appearance. The small, round crater (upper left) seems almost gemlike in its setting against the larger crater ring. But this companionship is no easy romance. Whatever formed the small crater clearly whammed into the larger crater rim at some point, obliterating part of its edge. You can tell the small crater was formed after the first and more devastating impact, because it is laid over the other larger crater. How much younger is the small one? Well, its rim is also much sharper and more intact, which gives a sense that it is probably far more youthful than the very degraded, ancient crater. |
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Clouds in the Northern Tempe
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PIA03787
Sol (our sun)
Thermal Emission Imaging Sys
…
| Title |
Clouds in the Northern Tempe Terra |
| Original Caption Released with Image |
(Released 2 May 2002) The Science This THEMIS visible image shows a region in northern Tempe Terra near 48° N, 75° W (285° E). Patchy water-ice clouds cover portions of the low-lying canyon at the top (north) of this image. Further south the atmosphere is clear and the knobby or "scabby" plains that are typical of many mid-latitude regions on Mars can be seen. These plains appear to mantle and modify a pre-existing surface, burying the older cratered terrain. This mantling layer has itself been modified to produce a pitted, knobby surface. The large mesa seen in this image has unusual deposits of material that occur preferentially on the cold, north-facing slopes. These deposits are seen frequently at mid-northern and southern latitudes, and have a distinct, rounded boundary that typically occurs at approximately the same distance below the ridge crest. It has been suggested that these deposits once draped the entire surface and have since been removed from all but the north-facing slopes. The presence of water ice in these layers is a likely possibility to account for their preservation only on the colder surfaces. The south-facing slopes lack this mantling material, and show clear evidence for layering in the rock units that form the mesa. The Story This deep and murky-looking depression is in an area called "Tempe Terra," a lilting, alliterative name that seems almost a little too merry for this kind of terrain. If the top of the image looks a little smudgy, that's because patchy water-ice clouds hang over the low lying canyon. Further south, where the air is clear, you can see some "scabby" plains (particularly in the high-res image, where the knobby patches of raised surface areas sort of do look like crusted-over dirt wounds). These plains cover a more ancient, cratered surface, but have been eroded away enough to form these scabby-seeming features. The large mesa in this image has some odd deposits of material on its cold, north-facing slopes. Could these deposits have been all over the surface of Mars long ago, but then were subsequently eroded away in most places on the planet? Did water ice on the colder surfaces preserve the last vestiges of these deposits so that scientists have the advantage of studying them today? While those answers won't be clear for a while, the south-facing slopes don't have this piled on material. That makes it easier to see the rock layers in the mesa. Layers are important to study, because they tell what has happened to the planet geologically over its history. The bottom layers are usually the oldest (unless some geologic force has pushed them up), so looking at each layer can give an idea of what happened first and last . . . and maybe even how long each period of time lasted. |
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Clouds in the Northern Tempe
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PIA03787
Sol (our sun)
Thermal Emission Imaging Sys
…
| Title |
Clouds in the Northern Tempe Terra |
| Original Caption Released with Image |
(Released 2 May 2002) The Science This THEMIS visible image shows a region in northern Tempe Terra near 48° N, 75° W (285° E). Patchy water-ice clouds cover portions of the low-lying canyon at the top (north) of this image. Further south the atmosphere is clear and the knobby or "scabby" plains that are typical of many mid-latitude regions on Mars can be seen. These plains appear to mantle and modify a pre-existing surface, burying the older cratered terrain. This mantling layer has itself been modified to produce a pitted, knobby surface. The large mesa seen in this image has unusual deposits of material that occur preferentially on the cold, north-facing slopes. These deposits are seen frequently at mid-northern and southern latitudes, and have a distinct, rounded boundary that typically occurs at approximately the same distance below the ridge crest. It has been suggested that these deposits once draped the entire surface and have since been removed from all but the north-facing slopes. The presence of water ice in these layers is a likely possibility to account for their preservation only on the colder surfaces. The south-facing slopes lack this mantling material, and show clear evidence for layering in the rock units that form the mesa. The Story This deep and murky-looking depression is in an area called "Tempe Terra," a lilting, alliterative name that seems almost a little too merry for this kind of terrain. If the top of the image looks a little smudgy, that's because patchy water-ice clouds hang over the low lying canyon. Further south, where the air is clear, you can see some "scabby" plains (particularly in the high-res image, where the knobby patches of raised surface areas sort of do look like crusted-over dirt wounds). These plains cover a more ancient, cratered surface, but have been eroded away enough to form these scabby-seeming features. The large mesa in this image has some odd deposits of material on its cold, north-facing slopes. Could these deposits have been all over the surface of Mars long ago, but then were subsequently eroded away in most places on the planet? Did water ice on the colder surfaces preserve the last vestiges of these deposits so that scientists have the advantage of studying them today? While those answers won't be clear for a while, the south-facing slopes don't have this piled on material. That makes it easier to see the rock layers in the mesa. Layers are important to study, because they tell what has happened to the planet geologically over its history. The bottom layers are usually the oldest (unless some geologic force has pushed them up), so looking at each layer can give an idea of what happened first and last . . . and maybe even how long each period of time lasted. |
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Syrtis Major
PIA03786
Sol (our sun)
Thermal Emission Imaging Sys
…
| Title |
Syrtis Major |
| Original Caption Released with Image |
(Released 1 May 2002) The Science This image is from the region of Syrtis Major, which is dominated by a low-relief shield volcano. This area is believed to be an area of vigorous aeolian activity with strong winds in the east-west direction. The effects of these winds are observed as relatively bright streaks across the image, extending from topographic features such as craters. The brighter surface material probably indicates a smaller relative particle size in these areas, as finer particles have a higher albedo. The bright streaks seen off of craters are believed to have formed during dust storms. A raised crater rim can cause a reduction in the wind velocity directly behind it, which results in finer particles being preferentially deposited in this location. In the top half of the image, there is a large bright streak that crosses the entire image. There is no obvious topographic obstacle, therefore it is unclear whether it was formed in the same manner as described above. This image is located northwest of Nili Patera, a large caldera in Syrtis Major. Different flows from the caldera eruptions can be recognized as raised ridges, representing the edge of a flow lobe. The Story In the 17th century, Holland was in its Golden Age, a time of cultural greatness and immense political and economic influence in the world. In that time, lived a inquisitive person named Christian Huygens. As a boy, he loved to draw and to figure out problems in mathematics. As a man, he used these talents to make the first detailed drawings of the Martian surface - - only 50 years or so after Galileo first turned his telescope on Mars. Mars suddenly became something other than a small red dot in the sky. One of the drawings Huygens made was of a dark marking on the red planet's surface named Syrtis Major. Almost 350 years later, here we are with an orbiter that can show us this place in detail. Exploration lives! It's great we can study this area up close. In earlier periods of history, scientists were fascinated with Syrtis Major because this dark region varied so much through the seasons and years. Some people thought it might be a changing sea, and others thought it might be vegetation. Early spacecraft like Mariner and Viking revealed for the first time that the changes were caused by the wind blowing dust and sand across the surface. What we can see in this image is exactly that: evidence of a lot of wind action. Bright dust patches streak across this image, formed through wind interference from craters and other landforms. These wispy, bright streaks are spread on the surface by a vigorous, east-west wind that kicked up huge dust storms, scattering the fine particles of sand and dust in an almost etherial pattern. The bright streaks in the top part of the image might have formed in a slightly different way, because there is no landform standing in the wind's way. Beneath the bright surface dust are raised ridges that mark the edges of earlier lava flows, from Nili Patera, a Martian "caldera." A caldera is a collapsed, bowl-shaped depression at the top of a volcano cone. Can you imagine how Christian Huygens would feel if he lived today and could see all of this knowledge unfold? Or how it would feel to be the first person to stand in this dark volcanic and cratered region, knowing how many discovers had paved the way to that moment? Yes, exploration lives! |
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Syrtis Major
PIA03786
Sol (our sun)
Thermal Emission Imaging Sys
…
| Title |
Syrtis Major |
| Original Caption Released with Image |
(Released 1 May 2002) The Science This image is from the region of Syrtis Major, which is dominated by a low-relief shield volcano. This area is believed to be an area of vigorous aeolian activity with strong winds in the east-west direction. The effects of these winds are observed as relatively bright streaks across the image, extending from topographic features such as craters. The brighter surface material probably indicates a smaller relative particle size in these areas, as finer particles have a higher albedo. The bright streaks seen off of craters are believed to have formed during dust storms. A raised crater rim can cause a reduction in the wind velocity directly behind it, which results in finer particles being preferentially deposited in this location. In the top half of the image, there is a large bright streak that crosses the entire image. There is no obvious topographic obstacle, therefore it is unclear whether it was formed in the same manner as described above. This image is located northwest of Nili Patera, a large caldera in Syrtis Major. Different flows from the caldera eruptions can be recognized as raised ridges, representing the edge of a flow lobe. The Story In the 17th century, Holland was in its Golden Age, a time of cultural greatness and immense political and economic influence in the world. In that time, lived a inquisitive person named Christian Huygens. As a boy, he loved to draw and to figure out problems in mathematics. As a man, he used these talents to make the first detailed drawings of the Martian surface - - only 50 years or so after Galileo first turned his telescope on Mars. Mars suddenly became something other than a small red dot in the sky. One of the drawings Huygens made was of a dark marking on the red planet's surface named Syrtis Major. Almost 350 years later, here we are with an orbiter that can show us this place in detail. Exploration lives! It's great we can study this area up close. In earlier periods of history, scientists were fascinated with Syrtis Major because this dark region varied so much through the seasons and years. Some people thought it might be a changing sea, and others thought it might be vegetation. Early spacecraft like Mariner and Viking revealed for the first time that the changes were caused by the wind blowing dust and sand across the surface. What we can see in this image is exactly that: evidence of a lot of wind action. Bright dust patches streak across this image, formed through wind interference from craters and other landforms. These wispy, bright streaks are spread on the surface by a vigorous, east-west wind that kicked up huge dust storms, scattering the fine particles of sand and dust in an almost etherial pattern. The bright streaks in the top part of the image might have formed in a slightly different way, because there is no landform standing in the wind's way. Beneath the bright surface dust are raised ridges that mark the edges of earlier lava flows, from Nili Patera, a Martian "caldera." A caldera is a collapsed, bowl-shaped depression at the top of a volcano cone. Can you imagine how Christian Huygens would feel if he lived today and could see all of this knowledge unfold? Or how it would feel to be the first person to stand in this dark volcanic and cratered region, knowing how many discovers had paved the way to that moment? Yes, exploration lives! |
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