There have actually been at least five major ice ages since Earth formed about four and a half billion years ago. And believe it or not, the last ice age could still be happening right now.

Earth has gone through a lot of changes in its 4.5 billion years. At certain times the climate has resembled a humid mix of water vapor and solar radiation. Other times, cold snaps lasting millions of years have turned our planet into something more resembling the planet Hoth from Star Wars. Scientists are still trying to fully understand how an ice age happens—and why it may still be happening.

In this episode of Misconceptions, host Justin Dodd thaws out a few myths about the ice age, from the idea that Earth was once frozen solid to what actually caused the mammoths’ extinction.

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This article was originally published on www.mentalfloss.com as Misconceptions About the Ice Age.