United States

Mars took way longer to form than astronomers realized

Mars may have taken as long as 20 million years to form, scientists now claim. The new timescale rewrites Martian history – as it was previously thought Mars formed in as little as 2 million years. Scientists are constantly trying to map out our solar system’s past. One of the big questions is: how did the planets form and how long did it take? Now experts have modeled the birth of Mars and think it happened surprisingly slowly. Early in Martian history, the planet was likely struck by small protoplanets around 1,200 miles across. Scientists have tried to model how the materials associated with these impacts mixed. Around 200 meteorites than have turned up on Earth are believed to be Martian in origin. They feature elements like ...