Traces of an ancient coastline have been found on Mars.

Scientists from the University of Pennsylvania have found traces of a coastline on Mars that are about 3.5 billion years old. This proves that there used to be an ocean on the planet. Its outlines were revealed thanks to topographic maps. On Mars, it was possible to see more than 6500 km of ridges that form 20 systems. These are the deltas of the former Martian rivers and underwater channels - the remnants of the coastline. The data that scientists have received shows that once the ocean level rose on Mars, which means there was a warm and humid climate.