A new study suggests that the Chelyabinsk meteorite that exploded over Russia in 2013 could also be involved in the massive impact that formed the moon.
The researchers, led by the University of Cambridge, believe it could be part of an ancient collision that broke off a piece of the young Earth 4.5 billion years ago and formed the Moon.
It is believed that a Mars-sized body crashed into our planet during the formation of the solar system, throwing a bunch of material into space, which then combined to form the moon.
Nine years ago, Chelyabinsk, 60 feet (19 meters) wide, collided with the Earth’s atmosphere with the energy equivalent of 500,000 tons of TNT, sending a shock wave around the globe twice.
This caused significant damage and injured more than 1,600 people.
A new study suggests that the Chelyabinsk meteorite (pictured), which exploded over Russia in 2013, could also have been involved in the powerful impact that formed the moon.
Using uranium-lead dating, scientists previously discovered that the Chelyabinsk meteorite underwent two impacts, one about 4.5 billion years ago and the other about 50 million years ago.
WHAT IS THE CHELYABINSK METEOR?
The meteor that swept over the southern Urals in February 2013 was the largest recorded meteor strike in more than a century.
More than 1,600 people were injured in the blast from an explosion estimated to be as powerful as 20 atomic bombs dropped on Hiroshima that landed near the city of Chelyabinsk in Russia.
A fireball 18 meters in diameter crashed into the Earth’s atmosphere at a speed of 41,600 miles per hour. Most of the meteorite fell into a local lake called Chebarkul.
In addition to the latest find, after the February 15 incident, scientists have already found more than 12 items in Chebarkul Lake. However, only five of them turned out to be real meteorites.
The discovery came to light thanks to a new way of dating collisions between rocks in space, based on the microscopic analysis of minerals in meteorites.
Further research is still needed, but scientists hope this method will help them learn more about the early history of the solar system and how it evolved to its current form.
“The age of a meteorite impact is often controversial,” said geologist Craig Walton of the University of Cambridge.
“Our work shows that we need to rely on multiple lines of evidence to be more confident in the history of collisions – almost like investigating an ancient crime scene.”
When the solar system formed from dust and gas, the planets were created as a result of repeated collisions of smaller rocks.
However, it is difficult to trace the history of the Earth and other similar bodies from the very beginning, because geological and weather processes have rewritten it.
This does not apply to asteroids and meteorites.
They haven’t changed much while flying in space, which means they serve as a great time capsule to look back to the origins of the solar system.
One way to do this is to study ancient collisions of minerals found in meteorites that have fallen to Earth, using uranium-lead dating in zircon crystals.
The scientists studied the microscopic details of the destruction of phosphate minerals and found that an earlier collision ripped them into small pieces and exposed them to high temperatures.
They found that the later impact seemed smaller at lower pressures and temperatures, so it probably happened less than 50 million years ago. They also believe that this was the impact that tore the meteorite away from its larger parent body and sent it on a collision course with Earth.
When formed, zircon incorporates uranium but rejects lead.
This means that any lead found in zircon must be a radioactive decay product of uranium, so since experts know how long it takes for uranium to decay, they can determine the age of zircon from the lead component.
Moreover, the collision can also partially or completely “reset” the radioisotope mineral age.
Using this analysis, scientists previously determined that the Chelyabinsk meteorite had two impacts, one about 4.5 billion years ago and the other about 50 million years ago.
Walton and his fellow researchers wanted to confirm these dates by studying how the phosphate minerals in the meteorite were destroyed by successive impacts.
“Phosphates in most primitive meteorites are fantastic objects for dating the impact events that meteorites have experienced on their parent bodies,” said geophysicist Sen Hu of the Chinese Academy of Sciences in China.
Researchers now want to revisit the timing of the moon’s formation in an attempt to shed more light on their theory.
The scientists studied the microscopic details of how the phosphate minerals broke down and found that an earlier collision ripped them into small pieces and exposed them to high temperatures.
They found that the later impact seemed smaller at lower pressures and temperatures, so it probably happened less than 50 million years ago.
They also believe that this was the impact that tore the meteorite away from its larger parent body and sent it on a collision course with Earth.
“The fact that all of these asteroids are showing intense melting at this time may indicate a reorganization of the solar system, either as a result of the formation of the Earth-Moon, or possibly as a result of the orbital motion of the giant planets,” Walton said.
Now the researchers want to revisit the timing of the moon’s formation to try and shed more light on their theory.
The study was published in the journal Communications Earth & Environment.