An Etymological Dictionary of Astronomy and Astrophysics

A major interval of geologic time during which extensive ice sheets (continental → glaciers) formed over many parts of the world.

There have been at least five significant ice ages in Earth’s history, with approximately a dozen epochs of glacial expansion occurring in the past 1 million years. The last one ran from about 75,000 to 15,000 years ago.

See also: → ice; → age.