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 CNNHow to Cool a Planet With Extraterrestrial Dust The New York TimesDust cloud sparked explosion in primitive life on Earth, say scientists The GuardianAn ancient asteroid may have had a delightful effect on Earth's ocean life InverseView full coverage on Google News