Aeon always has some great articles every month, and one of these is titled “The Snowball Effect.”
The article discusses two periods when glaciers covered the Earth from pole to equator. The last time was 645 million years ago, with the ice remaining for about 10 million years. Even so, life survived and diversified under these conditions on a super-continent called Rodinia.
It may offer some lessons to us when we are looking at our Solar System’s moons as well as distant exoplanets wondering about the presence of life beneath a frozen surface. If the Earth was a snowball for millions of years before life as we know it came to be, it makes sense it would be the case elsewhere.
I recommend you review this article as well as others on Aeon. It is worth your time.
Our Awesome Universe 