Nine yellow arrows point to Martian ooids with holes bored by microbes. You must see the photo’s original size (www.flickr.com/photos/fossil_lin/26127132276/sizes/o/) in order to see the holes in the ooids. NASA’s Mars Rover Curiosity acquired the above image with Mars Hand Lens Imager (MAHLI) on Jan. 23, 2016 (Sol 1231) at Namib Dune in Bagnold dune field, Gale Crater, Mars. Most of the particles in this image are ooid sand, although many of them have been severely eroded. Red lines mark some of the better-preserved ooids. They are all smaller than 1 mm across. Image width: ~2.8 cm. Image Credit: NASA/JPL-Caltech/MSSS Image source:www.flickr.com/photos/105796482@N04/24483811912/