Manganese deposits on Mars’ ancient lake hint at Earth-like conditions.

Manganese has been observed on Mars by the NASA Curiosity rover in multiple places, but a higher-than-usual amount has been detected in the Gale crater.

The ChemCam instrument onboard the rover detected the deposits, which indicate that the sediments had formed in a river, delta, or near the shoreline of an ancient lake.

These sedimentary rocks have larger grain sizes than what is typical for the lakebed rocks in the Gale Crater. This may indicate that the original sediments were formed in a river, delta, or near the shoreline of the ancient lake.