Tag: Mars Reconnaissance Orbiter

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Cool image time! The photo to the right, rotated and cropped to post here, was taken on June 17, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The section highlighted is at full resolution, in order to make clear the absolutely crazy and complex terrain seen in the full image.

This terrain is not glacial, as the location is only about 1 degree south of the Martian equator. There might have been surface or near surface ice here once in the past, but there is none now.

Could we be looking at some form of lava flow? This is possible, because a close look at the context map at the image link suggests this region has been partly covered by some material, obscuring some craters to the east and west. However, there is no visible evidence anywhere in this region of a volcanic vent or caldera. If this covering material was volcanic it is very unclear where it came from.

The overview map below does not really provide any answers, but at least gives the context.
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Cool image time! The photo above, rotated, cropped, and reduced to post here, was taken on May 13, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), and shows two dramatic ancient flows of flood lava. The arrows indicate what I think is the direction of flow for each, though the direction of the flow to the north appears more certain. In a wider context camera image the bulk of the evidence suggests the southern flow is heading west (as indicated by the arrow), but there are scalloped mesas within it that suggest the opposite.

The overview map above marks the location of this picture by the white cross inside the Athabasca Valles flood lava, thought by some scientists [pdf] to be Mars’ youngest major lava event that erupted about 600 million years ago and in just a matter of a few weeks poured out enough lava to cover an area about the size of Great Britain.

The general trend of the Athabasca flow was to the south, splitting into a big western and southeastern flows. This picture captures the southern edge of that southeastern flow, which might help explain why the flow directions in the picture seem so different from the main Athabasca flow. On a large scale, the flow was to the southeast. On a small scale at the edges the flow could go in many directions as the lava looks to find its level.

The Medusa Fossae Formation is the largest volcanic ash deposit on Mars, and is thought to be the source of most of the red planet’s dust. Though the origin of the ash is not yet known, it likely came from the eruptions that formed the planet’s giant volcanoes to the east and west.

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Today’s cool image provides further proof that there is ample near surface ice almost anywhere on Mars once you get above 30 degrees latitude, in either the northern or southern hemispheres. The photo to the right, rotated, cropped, reduced, and annotated to post here, was taken on May 26, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the interior slope of an unnamed 15-mile-wide crater that sits inside the much larger 185-mile-wide Newton crater, located in the cratered southern highlands of Mars.

The black cross on the global map of Mars above marks the location of this crater.

The photo was taken as part of the routine monitoring planetary scientists are doing of the gullies that flow down this crater’s interior rim, a monitoring program that goes back to 2007. It is thought that those gullies might be created by seasonal frost, either water ice or dry ice, that causes erosion.

What struck me about the photo however was the glacial features on the floor of the crater. Near the bottom of the interior slope those features look broken up, as if the pressure from above pushed the ice sheets apart. Farther from the interior slope the features more resemble a typical glacial flow, slowly inching downward toward the crater’s low spot. All these glacial features also lend weight to the theory that water ice somehow caused or contributed to the formation of those gullies.

The global map above shows that this crater, while well within the 30 to 60 degrees mid-latitude band where many Martian glaciers are found, is also far from the many regions on Mars that scientists have mapped as having high concentrations of glaciers. And yet, the glacial features are here as well.

Near surface ice will not be found at every spot on Mars. However, once you get above 30 degrees latitude, the evidence increasingly suggests that you won’t have to go far or dig down deep to find it.

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Cool image time! The photo to the right, rotated, cropped, and reduced to post here, was taken on April 21, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO) of a spot in the Martian northern lowland plains.

Generally the surface of these lowland plains — especially at high latitudes above 30 degrees — tends to appear very water saturated, producing blobby features and what look like mud volcanoes. This picture however features something different, what the scientists have labeled fractures, geological features that appeared caused by dry conditions and sudden quake-like events. The break in the fracture near the top of the photo illustrates why water flow had little if anything to do with its formation. Other fractures in the full image show the same thing. Also the stippled surface along the picture’s right edge also suggest there is little near surface water or ice at this location.

The location, as shown by the overview map below, suggests that water might still have played a part, but only a long time ago.
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