Fresh evidence suggests that microorganisms were involved in the enigmatic markings on Mars.

Scientists have explained the potential chemical signs of ancient life on Mars. This sign – the mark seen on rocks on Mars last year – may have been caused by microorganisms and reactions that occur only at high temperatures. New findings suggest that biological explanations are more likely.

Last year, while exploring the ancient lakebed called Bright Angels in Jezero Crater on Mars, NASA's patient rover discovered a rock with an unusual marking called “Leon.”