Newslink: 'Blueberries' on Mars Have a Watery Past. But Scientists Are Still Baffled.

Snack-loving scientists working with the Opportunity mission on Mars dubbed tiny, iron-rich spheres scattered near the robot's landing site "blueberries," but these features were easier to name than to understand.

https://www.space.com/42645-mars-blueberries-formation-mystery-earth-analogs.html