Eye of Sahara appears on Mars, could have once carried water to surface
The eye of Sahara, a geological formation that was first photographed by Gemini astronauts in the 1960s, has been a mysterious phenomenon for decades. A similar structure has now been seen on Mars, where a 30 km-wide unnamed crater has been seen in the Aonia Terra region.
The image captured by the European Space Agency's Mars Express shows part of Aonia Terra, an upland region in the southern highlands of the Red Planet. The crater is in the center of a landscape of winding channels that appear like veins running through a human eyeball.
Astronomers suspect that the channels are likely to have carried liquid water across the surface of Mars around 3.54 billion years ago. According to ESA, the channels look as if they are partly filled with a dark material, and in some places, seem to actually be raised above the surrounding land.
" There are a variety of possible explanations for this. Perhaps erosion-resistant sediment settled at the bottom of the channels when water flowed through them. Or perhaps the channels were filled in with lava later on in Mars' history," ESA said in a statement released with the image.
This oblique perspective view of part of the scarred and colourful landscape that makes up Aonia Terra, an upland region in the southern highlands of Mars. (Photo: ESA)
The image snapped by the probe earlier this month reveals the different colours on the surface, suggesting that this region of Mars is made up of a variety of materials. While on the south of the crater (on the left of the true-colour image above), the surface is a warm red, melting into a darker brownish-grey closer to the crater, inside the crater, a dark dune field rests on a lighter surface.
The image also reveals buttes, the flat-topped towers of rock, created when land is gradually worn away by water, wind, or ice. " This is evidence that many different materials accumulated inside the crater," ESA said.
The Aonia Terra, named after a feature called Aonia, is a dark patch on the surface of Mars that can be seen from Earth, even with rudimentary telescopes. Aonia is derived from Greek mythology and was once a location sacred to the Muses, the goddesses of literature, science, and the arts in ancient Greece.
The Mars Express has been orbiting the Red Planet since 2003, imaging Mars' surface, mapping its minerals, identifying the composition and circulation of its tenuous atmosphere, probing beneath its crust, and exploring how various phenomena interact in the martian environment.