Eagle-eyed conspiracy theorists have identified what looks like a small pyramid on the Red Planet.
A lot of strange things have been spotted in photographs taken by the Mars rovers over the years and this week another anomalous object has been added to the list – a small stone pyramid.
Discovered in images recorded by the Curiosity rover, the pint-sized structure is alleged to be the top of a much larger pyramid that had become buried in the sand over thousands of years.
Critics however have argued that the anomaly is far more likely to be a geological formation as similar pyramid-shaped rocks carved by the wind have been found on the Earth.
Other objects seen previously in photographs of Mars have included coffins, traffic lights, a hamster and even a rock that seemed to bear an uncanny resemblance to US President Barack Obama.
“The vast majority of these images are as vague and elusive as those posted by UFO witnesses on Earth, and many have a fairly mundane explanation,” said author Nigel Watson.
“The problem is that the more Nasa denies such things or explains them, the more people think there is a conspiracy to hide the truth that aliens are visiting our planet.”