Data from China's Zhurong rover has revealed what appears to be an ancient shoreline streaking through Mars' northern hemisphere.
Happy Martian New Year! Today marks the start of a new year on the Red Planet , the 38th since humans began counting in 1956. The Martian new year begins with data from a now-defunct rover spotting what appears to be an ancient shoreline streaking through Mars ' northern hemisphere. Scientists studying data sent home by China's Zhurong rover say the findings offer fresh support to the decades-old hypothesis that an ancient ocean covered the Martian north billions of years ago. Since Zhurong landed in 2021 — in one of the largest and oldest impact basins on Mars, known as Utopia Planitia — the rover has traveled about 1.24 miles (2 kilometers) studying the geology of its surroundings in search of signs of water or ice. By combining observations from the rover's onboard cameras and ground-penetrating radar with remote sensing data from orbiting satellites, Bo Wu at Hong Kong Polytechnic University and his colleagues spotted several water-related features around the rover's landing area. They included crater-like pitted cones, troughs, sediment channels and mud volcano formations that the team interprets as evidence of an ancient coastline. Based on the composition of surface deposits in the area, the ocean likely existed around 3.68 billion years ago, according to a paper describing the findings, which was published in the journal Scientific Reports. The team thinks a variety of water-related minerals such as hydrated silica started forming on the ocean bed around this time. "The water was heavily silted, forming the layering structure of the deposits," study co-author Sergey Krasilnikov of the Hong Kong Polytechnic University told Reuters . The ocean then froze for about 10,000 to 100,000 years — a relatively short period in geologic timescales, etching out the observed coastline before drying out, roughly 260 million years later. Sign up for the Live Science daily newsletter now Get the world's most fascinating discoveries delivered straight to your…