Lava-filled Martian crater
Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on July 10, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the northeast corner of an unnamed 7-mile-wide crater, located near the equator in the dry Martian tropics.
The MRO science team labels this “crater and lava fill”, suggesting that the crater interior is filled with lava material. The nature of that crater floor reinforces this conclusion, as it is relatively smooth and does not have rough aspects of glacial material found in craters in the mid-latitudes. Instead, it looks like a frozen lake of lava that has the peaks of mostly buried features poking up at various spots.
What makes this crater interesting however are the gullies on the northern interior rim. Gullies on Mars are normally thought to be associated with some water-frost-ice process, probably seasonal, where the thaw-freeze cycle causes small collapses and avalanches. Yet, this crater is almost at the equator, in a very dry region where no evidence of near-surface ice is found. Gullies here suggest the hypothesis for explaining the gullies on Mars have not quite solved the mystery.
» Read more
Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on July 10, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the northeast corner of an unnamed 7-mile-wide crater, located near the equator in the dry Martian tropics.
The MRO science team labels this “crater and lava fill”, suggesting that the crater interior is filled with lava material. The nature of that crater floor reinforces this conclusion, as it is relatively smooth and does not have rough aspects of glacial material found in craters in the mid-latitudes. Instead, it looks like a frozen lake of lava that has the peaks of mostly buried features poking up at various spots.
What makes this crater interesting however are the gullies on the northern interior rim. Gullies on Mars are normally thought to be associated with some water-frost-ice process, probably seasonal, where the thaw-freeze cycle causes small collapses and avalanches. Yet, this crater is almost at the equator, in a very dry region where no evidence of near-surface ice is found. Gullies here suggest the hypothesis for explaining the gullies on Mars have not quite solved the mystery.
» Read more