Between 720 and 635 million years ago, during the Cryogenian Period, Earth experienced some of the most extreme climate conditions in its geologic history. Massive global glaciations, most notably the Sturtian and Marinoan events, are thought to have covered much of the planet in ice, possibly from pole to equator. This era is central to the Snowball Earth hypothesis, which proposes that continental landmasses and oceans were largely frozen over, triggered by decreased greenhouse gases and continental configurations that favored increased reflectivity from widespread ice and snow.

Studying rocks by day, dodging squirrels by snack time.