Space & Astronomy

Moon formation theory gets a new boost

By T.K. Randall
April 9, 2015

Image: Full Moon
Credit: Thom Rains / CC BY 3.0 (adapted) Despite being our nearest neighbor there is still a lot that we do not know about the moon. The process that led to its formation, an event that is believed to have occurred around 4.5 billion years ago, has always remained something of a mystery.

The most commonly accepted theory suggests that the moon was created from the debris produced by a cataclysmic collision between the Earth and another Earth-sized world during the tumultuous early days of the solar system.

The main problem with this theory however is that the moon should be mostly composed of material from this second planet whereas in practice it is actually almost identical in composition to the Earth.Now by running computer simulations of the collision Dr Hagai Perets and colleagues from the Technion-Israel Institute of Technology have discovered that the moon's composition could actually be explained by the impact scenario after all if the second planet was sufficiently similar to the Earth.

"What we found is that many of these impactors on a planet have very similar composition to that of the planets they impact - as similar as what we measure between the Earth and the Moon," said Dr Perets. "I am [now] even more confident about the giant impact hypothesis."

Two further studies conducted in the US and Germany also seemed to confirm that the composition of samples collected from the moon's surface supported the idea of a collision.

"The small, but significant, difference in the tungsten isotopic composition between Earth and the Moon perfectly corresponds to the different amounts of material gathered by Earth and the moon post-impact," said Prof Richard Walker from the University of Maryland.

Source: BBC News

Tags: Moon, Earth