Here on Earth, moles are small mammals that like to live underground. Spread all over North America, Europe and Asia, they give away their presence through so-called molehills, which are nothing more than mounds that mark the entrance to whatever tunnel the creatures dig in search of the worms they eat.
Of course, such mounds can form for a variety of other reasons, and they do not occur solely on our planet. Mars, for instance, has them too, and although we’d like to think some sort of creature is responsible for them, chances are reality is a lot less spectacular.
Take the image we have here, released by the University of Arizona not long ago and showing a crater in the Arabia Terra region of Mars, as seen by the HiRISE orbital camera from a height of 281 km (175 miles).
The crater looks like most others up there on the fourth planet from the Sun, only unlike many of the others, it is riddled with mounds with pits at their center, most probably not made by some creature, but most definitely a mystery for Earth scientists.
The people who discovered this hint do not know for sure what caused the features, but their most likely suspect is the omnipresent-on-Mars sublimation. That’s the process that takes something from a solid state to a gaseous one without going through liquid state.
“The crater itself is an ancient one, as evidenced by the eroded rim. For the mound inside, HiRISE resolution can give us a closer look at textural features that might help explain what we're looking at: layers in pit walls, or perhaps cracks from expansion?” scientists ask.
As for the Arabia Terra region, it lies at the north of the planet and is filled with craters and signs of erosion, which makes us think it may be one of the oldest features of the planet.
It’s also the place where Mark Watney, the main character of Andy Weir’s The Martian, fights a massive dust storm as he was trying to find ways off the planet after being left all alone up there.
Take the image we have here, released by the University of Arizona not long ago and showing a crater in the Arabia Terra region of Mars, as seen by the HiRISE orbital camera from a height of 281 km (175 miles).
The crater looks like most others up there on the fourth planet from the Sun, only unlike many of the others, it is riddled with mounds with pits at their center, most probably not made by some creature, but most definitely a mystery for Earth scientists.
The people who discovered this hint do not know for sure what caused the features, but their most likely suspect is the omnipresent-on-Mars sublimation. That’s the process that takes something from a solid state to a gaseous one without going through liquid state.
“The crater itself is an ancient one, as evidenced by the eroded rim. For the mound inside, HiRISE resolution can give us a closer look at textural features that might help explain what we're looking at: layers in pit walls, or perhaps cracks from expansion?” scientists ask.
As for the Arabia Terra region, it lies at the north of the planet and is filled with craters and signs of erosion, which makes us think it may be one of the oldest features of the planet.
It’s also the place where Mark Watney, the main character of Andy Weir’s The Martian, fights a massive dust storm as he was trying to find ways off the planet after being left all alone up there.