Enthusiasts lit up social media recently with images of what appeared to be a “doorway” into a hillside on Mars. Was it, some wondered, evidence that the red planet could be, or have been, inhabited by aliens? The “door” was imaged by Nasa’s Curiosity rover on May 7 on the slopes of Mount Sharp, the central massif within Gale crater, where it landed in 2012. Described on one website as a “pharaonic tomb door”, because of its resemblance to some ancient Egyptian remains, it is in fact only about one foot high.
It is hard to spot on the panoramic image mosaic of the hillside above, but it leaps out at the eye if you see the individual frame where it occurs, seen below. It does look like a doorway until you realise how small it is. And if you boost the contrast in the dark parts of the image, the picture just about reveals a solid rock face at the back of the shadowed interior. So as a gateway into the hollow hills of Mars, it doesn’t lead very far.
