NASA's Curiosity rover has captured a photo of a strange rock formation on Mars, which some experts have called the "most bizarre" they've ever seen. The structure appears to show spikes protruding from a rock at the base of the Gale Crater, where the rover has been exploring since 2012 as part of NASA's Mars Science Laboratory (MSL) mission. Social media users have suggested various possibilities, including that it could be a fossilized plant or fish bone, although some speculate that Martian winds may have eroded the rocks over time.
