China’s Mars rover finds hints of catastrophic floods

China’s Zhurong rover has peered under the surface of Mars — down to 100 metres — and has found evidence of two huge floods that shaped the landscape. Since May last year, Zhurong has been exploring Utopia Planitia, in Mars’s northern hemisphere. Images from the rover’s ground-penetrating radar found layered patterns under the surface, which the authors suggest are made of sedimentary rocks carried in by two major floods around 3 billion and 1.6 billion years ago. But other scientists say that, although radar is good at detecting layers of subsurface material, it’s less proficient at identifying what layers are made of.