Was there ever life on Mars? That is one of the longest-running and most debated questions in planetary science, and while there have been tantalizing clues, solid evidence has been elusive. Now there is a new piece to add to the puzzle, which may be one of the most interesting yet. As first reported on Smithsonian.com, odd formations composed of silica seen by the Spirit rover, nicknamed “cauliflower” for their shapes, may have been produced by microbes, new research suggests. They are very similar to some silica formations on Earth which are found in hydrothermal environments and are known to have formed with the help of microscopic organisms.