... and glaciations... GOOGLE RESULT: Did Snowball Earth exist? NASA GISS: Research Features: "Snowball Earth" Might Have ... "Hard or slushy. Scientists contend that at least two Snowball Earth glaciations occurred during the Cryogenian period, roughly 640 and 710 million years ago. Each lasted about 10 million years or so." SOURCE: Research Features: "Snowball Earth" Might Have Been Slushy nasa.gov https://www.giss.nasa.gov › features › 201508_slushball SEE ALSO (if you really want to learn more ;-)...): https://en.wikipedia.org/wiki/Cryogenian https://en.wikipedia.org/wiki/Snowball_Earth https://en.wikipedia.org/wiki/Ice_age |