The uniquely-shaped pebble resembles an open book.
NASA's Curiosity Mars Rover was able to take a close-up picture of a rock that resembled a book on April 15, 2023, which helped scientists learn more about the atmosphere and ecosystem on Mars.
"Terra Firme" is the nickname given to the rock, which resembles a book's open pages. Using the Mars Hand Lens Imager (MAHLI) on the end of its robotic arm, the rover discovered it on the 3,800th day of its mission on Mars. The rock measures roughly 2.5 cm across.
On Twitter, the official account for the Curiosity Rover posted: "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...)."
According to NASA, rocks with unusual shapes are common on Mars and were often formed by water seeping through cracks in a rock in the ancient past, bringing harder minerals along with them. After aeons of being sandblasted by the wind, the softer rock is carved away, and the harder materials are all that's left.
"NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, leads the Curiosity mission. Curiosity took the selfie using a camera called the Mars Hand Lens Imager (MAHLI), located on the end of its robotic arm. MAHLI was built by Malin Space Science Systems in San Diego."