An asteroid impact is an extremely powerful event. Depending on a variety of factors, ranging from the size and composition of the asteroid to the angle of the hit, such impacts have the potential of forever altering the history of a planet.
With that in mind, one could say craters, the results of such hits, will forever scar the surface of any world. And for what it’s worth, they do, as seen times and again in the photos sent back from Mars, for instance, by the HiRISE camera in orbit around the planet.
But there are some forces that are even more powerful than asteroid impacts, even if it takes a hell of a lot more for them to manifest. So powerful, in fact, that not even craters can survive them intact.
It’s geologic processes we’re talking about, which are natural events that happen over centuries and large distances. And even if now it looks mostly dead, Mars was once very much active in this sense as well.
And the effects of geologic processes couldn’t be clearer than in the main photo of this piece, showing an ancient (or what’s left of it) crater in the Nereidum Montes region of the planet. Once probably a very proud hole in the ground, it is now reduced to a semblance of a cartoonish face, with spiky hair on top and the tongue sticking out.
The people from NASA and the University of Arizona, who are studying images such as this, identified several reasons why the crater looks so peculiar.
First up would be “terrain-altering or -burying processes” that have erased almost the entire ejecta pattern around the crater. Then, its floor, which seems strangely flat, was probably filled over time with material, brought there by some long-lost force. The floor is surrounded by short walls, another indication of material filling in the crater.
Lastly, we have the gullies on the northern wall, and an “arc-shaped ridge inside the southern edge of the crater, partially buried by the filling material” that has scientists scratching their heads, as it “could be a wind-caused or other accumulation of crater-fill material.”
HiRISE captured this image back in 2011, from an altitude of 253 km (158 miles).
But there are some forces that are even more powerful than asteroid impacts, even if it takes a hell of a lot more for them to manifest. So powerful, in fact, that not even craters can survive them intact.
It’s geologic processes we’re talking about, which are natural events that happen over centuries and large distances. And even if now it looks mostly dead, Mars was once very much active in this sense as well.
And the effects of geologic processes couldn’t be clearer than in the main photo of this piece, showing an ancient (or what’s left of it) crater in the Nereidum Montes region of the planet. Once probably a very proud hole in the ground, it is now reduced to a semblance of a cartoonish face, with spiky hair on top and the tongue sticking out.
The people from NASA and the University of Arizona, who are studying images such as this, identified several reasons why the crater looks so peculiar.
First up would be “terrain-altering or -burying processes” that have erased almost the entire ejecta pattern around the crater. Then, its floor, which seems strangely flat, was probably filled over time with material, brought there by some long-lost force. The floor is surrounded by short walls, another indication of material filling in the crater.
Lastly, we have the gullies on the northern wall, and an “arc-shaped ridge inside the southern edge of the crater, partially buried by the filling material” that has scientists scratching their heads, as it “could be a wind-caused or other accumulation of crater-fill material.”
HiRISE captured this image back in 2011, from an altitude of 253 km (158 miles).