A crater that looks like a huge, unblinking eye has been photographed on the surface of Mars.
The stunning image – captured by a spacecraft orbiting the Red Planet – shows the crater in Aonia Terra, an upland region in the southern highlands of Mars.
The photograph was taken by the European Space Agency's (ESA) Mars Express on April 25.
The 19-mile unnamed crater at the centre of the image is nestled within a landscape of winding channels, which are likely to have carried liquid water across the surface of Mars around 3.5 to 4 billion years ago.
The channels appear to be partly filled with a dark material and, in some places, seem to actually be raised above the surrounding land.
Researchers said there were a variety of possible explanations for this – possibly erosion-resistant sediment settled at the bottom of the channels when water flowed through them, or the channels were filled in with lava later in Mars’ history.
Inside the crater, a dark dune field rests on a lighter surface. Upon closer inspection, it becomes apparent that the crater is filled with more buttes and cone-shaped hills.
These is evidence that many different materials accumulated inside the crater.
Aonia Terra is known for its impressive craters. Close to the crater shown in this image is the 124 mile-wide Lowell crater.
Lowell is thought to have been formed almost four billion years ago, during the solar system’s 'Late Heavy Bombardment' period, when a large number of asteroids crashed into the rocky planets.
Aonia Terra is named after a feature called Aonia, a dark patch on the surface of Mars that can be seen from Earth, even with rudimentary telescopes.
Of course, the crater is not an eye – or, indeed, biological in any way – but highlights the human tendency to see biological features in inorganic objects.
In the 1970s, a Nasa image of Mars seemed to show a human-like face, prompting observers to wonder if a lost civilisation once flourished on the Red Planet.
But the 'face on Mars' wasn’t evidence of any Martian civilisation – it just showed the human tendency to see human faces in everything from plants to rocks to houses.
A study by researchers from UNSW Sydney has shed light on why exactly humans are wired to see faces everywhere we look.
In a paper published in the journal Psychological Science, lead researcher Dr Colin Palmer said that 'face pareidolia' – the phenomenon of seeing faces in everyday objects – is related to how we see and understand real human faces.
Palmer said: "Pages on websites like Flickr and Reddit have accumulated thousands of photographs of everyday objects that resemble faces, contributed by users from across the world.
"A striking feature of these objects is that they not only look like faces but can even convey a sense of personality or social meaning.
"For example, the windows of a house might feel like two eyes watching you, and a capsicum might have a happy look on its face.
"This basic pattern of features that defines the human face is something that our brain is particularly attuned to, and is likely to be what draws our attention to pareidolia objects.
“But face perception isn’t just about noticing the presence of a face. We also need to recognise who that person is, and read information from their face, like whether they are paying attention to us, and whether they are happy or upset."
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