Did a Massive Asteroid Bring an End to Snowball Earth?

An ancient glaciation period 2.2 billion years ago may have come to an end when an enormous asteroid collided with Earth, a new study reveals.

Snow and ice covered the Earth billions of years ago, forming the Paleoproterozoic snowball Earth. This frigid era, which began as new lifeforms flooded the atmosphere with oxygen, ended as a massive meteor impacted Earth, a new study reveals.

The impact in the frozen tundra that is now Western Australia released hundreds of trillions of kilograms of water vapor into the atmosphere, raising temperatures around the globe, freeing Earth from its frozen existence.

The planet has undergone several eras of being a “Snowball Earth,” and one such event could have come to an end 2.2 billion years ago, following an impact between the Earth and a massive asteroid. Image credit: NASA

The Paleoproterozoic Era began 2.5 billion years ago (BYO), as the continents formed from groups of islands, and cyanobacteria (blue/green algae) first came into being. This period in the history of Earth would last for 900 million years.

Do You Want Ice in That?

As cyanobacteria performed photosynthesis, they flooded the atmosphere with oxygen for the first time. Earth lost the ability to retain warmth, and ice began to creep in from its home at the poles, toward the equator. Primitive anaerobic life was poisoned by the newly-altered atmosphere, or was driven out of their habitats by encroaching frigid conditions.