First, what is an ice age? It’s when the Earth has cold temperatures for a long time – millions to tens of millions of years – that lead to ice sheets and glaciers covering large areas of its surface.

When you buy through links on our articles, Future and its syndication partners may earn a commission. Regular changes in Earth's orbit and axial tilt may have triggered the start and end of ice ages ...

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to curiouskidsus@theconversation.com. How many ice ages has the Earth had, and could ...