Experts have spotted what they say looks like a book on the Red Planet. NASA’s Curiosity Mars rover captured a close-up view of a rock nicknamed “Terra Firme” last month.
The rock is about an inch across (2.5 cm) and the space agency report "looks like the open pages of a book".
The rover used its Mars Hand Lens Imager (MAHLI) on the end of its robotic arm to snap the puzzling picture on April 15, or the 3,800th Martian day.
NASA explain: "Rocks with unusual shapes are common on Mars, and often were formed by water seeping through cracks in a rock in the ancient past, bringing harder minerals along with them.
"After eons of being sand-blasted by the wind, softer rock is carved away and the harder materials are all that’s left."
The official Curiosity rover social media account commented: "Just doing some light reading. My team thinks this uniquely-shaped pebble resembles an open book with pages blowing in the wind. (Though at only an inch across, it would be a teeny tiny book...)."
Online comments have included "This may not be, but it sure looks close. I didn’t think right angles occurred in nature," "It certainly looks like a book. An open book. Did you find any message written for you there?" and "cue the conspiracy theorists".
