Scientists have long theorized that Mars once had liquid water on its surface. Ground-penetrating radar (GPR) is a geophysical method that uses radar pulses to image the subsurface. Data from China's Zhurong rover now supports this theory, revealing potential evidence of ancient Martian shorelines. - China's Zhurong rover has discovered geological formations suggesting the presence of ancient beaches on Mars. - The data indicates that a large ocean, potentially named Deuteronilus, existed on Mars between 3.5 and 4 billion years ago. - The discovery was made using ground-penetrating radar, which allowed the rover to analyze the subsurface of the Martian surface. - The existence of an ancient ocean suggests that Mars once had a thicker atmosphere and a more hospitable climate, raising questions about the possibility of past life. - The findings add a new dimension to our understanding of Mars's history and the potential for past habitability.