Mysterious spheres discovered on Mars

Scientists are calling the formations "blueberries", as they are said to be extremely soft, sulphate-rich sandstone holding harder peppercorn-size dark spheres.

"There's dark, grayish material coating faces of the rocks and filling fractures in them. At least part of it is composed of blueberries jammed together as close as you could pack them. We've never seen anything like this before," said Cornell University's Steve Squyres, principal investigator for Opportunity.

The blueberries were found on a rock nicknamed "chocolate hills", which scientist Matt Golobek compared to a "blueberry sandwich".


/Digital Spy/