(Before It's News)
There are numerous minute and perfect spheres on Mars, such as Martian Blueberries and Martian ooids. All those Martian spheres were produced by microbes on Mars, because natural geological processes cannot produce perfect spheres (note 1). For a long time, geologists believe ooids on Earth were not produced by life. However, many recent studies (note 1) show that ooids on Earth are produced by microbes. Many of the perfect spheres on Earth and on Mars possess smooth surfaces, which also show they were produced by life rather than geological processes. Even Utah’s Moqui Marbles were produced by microbes, according to some geologists (note 2).
Note 2: see http://research.unl.edu/annualreport/2013/microbes-and-moqui-marbles/