The story about mushrooms on Mars is less convincing the more one looks into it.
Photo: NASA Instead of mushrooms, NASA calls them 'blueberries', but unlike the authors of the new paper, no one at the space agency actually thinks these tiny spheres are a sign of life, let alone a growing fruit or vegetable.
In 2004, the Opportunity rover discovered millions of these 'blueberries', and upon analysis they were determined to be composed of the iron oxide, hematite. About three centimetres across (1.2 inches), these balls of solidified hematite were unlike anything ever seen on Mars before. Embedded in the Martian rock, like blueberries in a muffin, NASA explains that these spheres of hematite were solidified in the presence of water and then slowly released by erosion.