Ageing Mars rover Opportunity has found evidence that the conditions for ancient life once existed on the Red planet.

Above NASA Photo: Preliminary interpretation points to

clay mineral content  due to intensive alteration by water.

Mars Rover Opprotunity has been wandering on Mars since 2004, and it is still producing useful science.
Its remarkable longevity has astounded and delighted Nasa officials, who initially expected that it would last for just 90 Martian days. Instead it is continuing to roll along the surface, 37 times longer than anybody thought it would.

Its latest discovery is one of its most exciting, Nasa officials said: an area of rock which was clearly weathered by large amounts of water, indicating that the conditions for life once existed on the planet.
The exposed  rock ( called "Esperance") is unlike any the rover has previously found, fractured and weathered by conditions that were "possibly favorable for life", Nasa said. The new pictures were taken at Cape York, an area on the rim of the massive Endeavour crater.