'Slushball Earth' Could Have Sheltered Early Life
New research suggests that Earth may not have been fully frozen during the Marinoan glaciation, an "extreme" 15-million-year-long ice age that occurred 650 million years ago. Instead, the planet was more "slushball Earth" than "Snowball Earth," with patches of open water existing in shallow mid-latitude seas. Researchers discovered evidence of a type of saltwater vegetation called benthic phototrophic macroalgae, indicating that habitable ocean conditions may have been more extensive than previously thought, and life could have sheltered in these open oceans as the Earth thawed at the end of the Marinoan ice age.