Scientists seem to have successfully confirmed the collision that led to the formation of the Earth and the Moon took place around 4.47 billion years ago by dating the ancient impact marks on meteors that crashed on Earth. The date of the Moon-forming clash also gives us a better chance of reckoning when the Earth came into being.
The study sheds more light on the collision that took place between young Earth and its sister planet (called ‘Theia’) during the final stages of our planet’s formation. Astronauts have always thought that the Moon was a part of young Earth as both their compositions are similar. There have been theories that as a result of the clash, large chunks of the our once young world and ‘Theia’ were hurled into space, leading to the creation of our lunar body.
But according to the study’s researchers, along with the formation of the Moon, smaller fragments were also ejected which collided with nearby asteroid belts. The magnitude of these collisions produced about 1000 times more heated material as compared to normal main belt collisions. Time and again, small asteroids from these neighboring belts crash on earth.
For the latest project, the investigators studied the ancient impact heating signatures in some of these stony meteorites that landed on our planet and modeled a time frame for the older Moon-forming impact. Their results coincide with earlier predictions of how our sole natural satellite was born, dating it to around 4.47 billion years.
The research has been published in the journal Science and a summary of the findings have been released on NASA’s Solar System Exploration Research Virtual Institute (SSERVI) webpage. The study was headed by Principal Investigator Bill Bottke, of the Institute for the Science of Exploration Targets (ISET) at the Southwest Research Institute along with Tim Swindle, director of the University of Arizona’s Lunar and Planetary Laboratory (LPL) and the SSERVI team.
The findings not only confirm that the Moon was formed about 4.47 billion years ago, but also lend an alternate way to carry out chronological mapping of the bombardment history of other ancient asteroids like ‘Vesta’.