Toronto: Icy planets once thought too cold to support life may have livable land areas, according to a study that challenges the typical assumption of what kinds of planets might be habitable. Scientists have long thought snowball planets — Earth-like planets with oceans frozen to the equator — were hostile to life because of the extreme cold. The study found some snowball planets might have areas of land near their equators that reach livable temperatures. “You have these planets that traditionally you might consider not habitable and this suggests that maybe they can be,” said Adiv Paradise, an astronomer and physicist at the University of Toronto in Canada.
The habitable zone is a range of distances from a star where a planet could theoretically have liquid water and temperatures warm enough to support life. Planets in the habitable zone can be warm and temperate like Earth, or entirely frozen, like snowball planets. “We know that Earth was habitable through its own snowball episodes, because life emerged before our snowball episodes and life remained long past it,” said Paradise, lead author of the study.