NASA's Curiosity rover discovers bone-like structure on Mars

NASA's Curiosity rover has captured an image of a strange rock formation on Mars that has been dubbed the 'most bizarre' by an expert. The images show spikes protruding from a rock lying at the base of the Gale Crater. Some have compared the structure to a fish bone or branch of a fir tree, and said it would be 'difficult for it to be a natural rock formation' here on Earth. Curiosity has been exploring the Gale Crater since August 2012 as part of NASA's Mars Science Laboratory mission.