Location of discovery: Mars
Source photo: http://mars.jpl.nasa.gov/msl/multimedia/raw/?rawid=0746ML0032080400205823E01_DXXX&s=746
Photo ID: Sol 746, Mastcam: Left (MAST_LEFT)
This round object is an ancient fossil. It is a sea sponge and very common on Earth. Compare the close up of the Mars ball and the Earth ball. You will notice an incredible similarity in their size, shape, and even indention. This is hard core evidence that ancient oceans teaming with life once existed.
