Get the Popular Science daily newsletter💡 Email address Sign up Thank you! Terms of Service and Privacy Policy. New samples collected and analyzed by NASA's Curiosity rover are pushing researchers closer than ever to finding out if Mars was once truly capable of supporting life. According to a paper published on April 18 in Nature, ancient geologic samples indicate the Red Planet at one time featured a carbon cycle—an atmospheric condition that's necessary for sustaining liquid water on the Martian surface. Taken together with previous evidence pointing to the existence of dried rivers, lakes, and possibly even oceans, it's looking increasingly likely that Earth's neighbor featured at least some form of life in its distant past. As with all of Curiosity's previous work, these latest discoveries come from inside the 96-mile-wide Gale Crater. Located about 4.5 degrees south of the Martian equator, Gale Crater formed following an asteroid or comet strike roughly 3.5 to 3.8 billion years ago. At one time, it likely hosted a large, beach-rimmed lake. Curiosity has traveled over 21 miles from its landing site since 2012, and has obtained multiple drill site samples from layers of Martian sediment beneath it. One of the mission's long term goals has…