At first glance a photograph of Mars released by NASA appears to show a doorway carved into the rock.
The grainy image, captured by the Curiosity rover last week, clearly shows a rectangular gap in the rockface and has, perhaps inevitably, spawned conspiracy theories that point to it as evidence of alien life on the red planet.
For as long as humans have looked up to the skies we have seen things that aren’t really there – whether pictures in constellations, a face on the moon or a “mysterious hut” spotted by Chinese scientists that turned out to be a boulder.
And the simple explanation for the “door” on Mars is actually contained within the photograph itself if you look more closely, scientists have said.
It shows evidence that the feature was formed through “normal geological processes”, Professor Sanjeev Gupta at Imperial College London explained to The Daily Telegraph.
A deep crack or fissure is visible inside the “door”, indicating a fracture in the rock – something that happens on both Mars and Earth and could have taken place any time in the past few hundred million years.
“The crack is a fracture and they are plentiful on Mars and Earth – no need for marsquakes to produce them,” said Professor Gupta, who has worked on the Curiosity mission with NASA.
“There is nothing at all strange in the image –