Showing posts with label NASA. Show all posts
Showing posts with label NASA. Show all posts

Wednesday, May 4, 2016

A 4.5 Billion-Year-Old Mystery

Fig.1. An artist’s concept of two celestial bodies the size of Mercury (left) 
and the Moon (right) colliding (Credit: NASA/JPL-Caltech, 2009)

Long before an asteroid hit Earth, killing off all non-avian dinosaurs, a much larger object crashed into our planet. This object, called Theia, is thought to have collided with proto-Earth around 4.5 billion years ago. Scientists think that a glancing blow shaped our early planet and created the Moon out of Theia’s remains. A recent article published in Science, however, may overturn this hypothesis regarding the formation of the Moon.