Theia tagged posts

This is astronaut Alan B. Shepard Jr. on the moon in 1971 with the Apollo 14 mission. Credit: NASA

Formation occurred 4.51 billion years ago, 40 million to 140 million years older than scientists previously thought A UCLA-led research team analysed minerals from the moon called zircons that were brought back to Earth by the Apollo 14 mission in 1971. The moon’s age has been a hotly debated topic, even though scientists have tried to settle the question over many years and using a wide range of scientific techniques. “We have finally pinned down a minimum age for the moon; it’s time we knew its age and now we do,” said Mélanie Barboni, geochemist in UCLA.

The moon was formed by a violent, head-on collision between the early Earth and a “planetary embryo” called Theia, a UCLA-led team of ge...

This image shows from left Paul Warren, Edward Young and Issaku Kohl. Young is holding a sample of a rock from the moon. Credit: Christelle Snow/UCLA

The moon was formed from a violent, head-on collision between early Earth and ‘planetary embryo’ called Theia ~100 million years after the Earth formed, almost 4.5 billion years ago. Many thought Earth collided with Theia at 45 degrees or more. New evidence substantially strengthens the case for a head-on assault.

The researchers analyzed seven rocks brought to the Earth from the moon by the Apollo 12, 15 and 17 missions, as well as 6 volcanic rocks from the Earth’s mantle – 5 from Hawaii and 1 from Arizona. The key to reconstructing the giant impact was a chemical signature in the rocks’ O atoms...