Gigantic asteroid collision 470 million years ago caused Earth to freeze over, scientists say The IndependentA giant asteroid crash caused an ancient ice age on Earth, but also gave life a boost CNNDust cloud sparked explosion in primitive life on Earth, say scientists The GuardianHow to Cool a Planet With Extraterrestrial Dust The New York TimesDust from a giant asteroid crash caused an ancient ice age Phys.orgView full coverage on Google News