Geological map points to ancient seas on Mars Astronomy Now

A geological map, created using data from a plethora of orbiting spacecraft, presents new evidence that lakes persisted early in Mars’ history.
The map focuses on Hellas Planitia, an area located in the planet’s southern hemisphere that is well known for its giant impact basin – the Hellas basin – which spans over 2,000 kilometres in diameter and plunges to a depth of eight kilometres.