According to a paper published in the latest issue of Earth and Environment Communications, geoscientists at the University of Cambridge in the United Kingdom believe that the Chelyabinsk meteorite that exploded over Russia in 2013 may have been involved in the huge impact that formed the moon, which may be part of an ancient collision 4.5 billion years ago.
4.5 billion years ago, a Mars-sized object is thought to have crashed into a young Earth during the formation of the solar system, ejecting a pile of material into space and then coalescing together to form the moon.
The remains of the Chelyabinsk meteorite that exploded over Russia in 2013.
Nine years ago, the 60-foot-diameter (19-meter) Chelyabinsk meteorite fell into earth's atmosphere, with an estimated energy equivalent to 500,000 tons of TNT explosives, producing two shockwaves around the globe that caused widespread damage and injured more than 1,600 people.
Geoscientists at the University of Cambridge analyzed the minerals in the meteorite and thought that the meteorite might have been involved in the huge impact that formed the moon.
This new research method is to measure the lead isotope in zircon crystals, since the lead in zircon crystals is the product of uranium radioactive decay, according to the lead isotope content can be measured the age of zircon crystals, "reducing" the age of the large impact.
Based on the isotope content of lead in the meteorite, the age of the zircon crystal can be measured, and the age of the great impact can be "restored".
Using this analysis, scientists previously found that the Chelyabinsk meteorite experienced two impact events, one 4.5 billion years ago and the other about 50 million years ago.
In addition, the scientists studied the microscopic details of how phosphate minerals break up, and found that early impacts blew them into small pieces and exposed them to high temperatures.
The team found that later impacts appeared to have lower pressure and temperature, so it was likely to have occurred less than 50 million years ago. It was this impact that separated the meteorite from its larger parent body and sent it into an orbit that collided with Earth.
Craig Walton, an earth scientist at the University of Cambridge, said all of these asteroids had recorded intense melting at this time, a fact that could suggest that the recombination of the solar system was either caused by the formation of the Earth-Moon or the orbital motion of the giant planets.
The researchers now want to re-study the moon's formation time in an attempt to provide more evidence for their theory.
Text/Nandu reporter Chen Lin