Water movement detected in meteorites that fell to Earth within the past century
In a recent research, a team of scientists has revealed the evidence suggesting the water movement in meteorites that only recently fell to Earth.
The team studied the carbonaceous chondrite (CC) meteorites that fell on the Earth’s surface within last century.
Many scientists believe in the idea that water on Earth was once brought by meteorites.
However, previous studies to prove this went futile as meteorites recovered to date shows that the chemical reactions inside them involving liquid water stopped billions of years ago.
So now, scientists investigated the meteorites with a different approach. They analysed the isotopes in meteorites, which have fallen to Earth just within the last century.
Past research has suggested that (almost) most of the CC meteorites were formed about 4.5 billions years ago and were part of larger asteroids.
In order to trace the evidence of water on recently fell meteorites, scientists studied the distribution of thorium and uranium isotopes. Uranium is water soluble while thorium is not.
If water was indeed present on the meteorites, then it should have moved from one part of the rock to another, as the ice melted. This movement should be reflected in the distribution of uranium and thorium isotopes.
Also, the uranium and thorium have short half lives. This means that if the distribution of these isotopes is found on these meteorites, they would have occurred within the past one million years.
While studying nine of the meteorites, scientists found the pattern of thorium and uranium suggesting that water had flown on these meteorites due to melting of ice within the last one million years.
Scientists suggest that along with supplying water during the Earth’s early days, these meteorites could also have supplied water to Earth in the recent past.
This idea could be tested if the sample is obtained before striking Earth or taken directly from asteroids. For example, as was done recently by JAXA’s Hayabusa 2 and NASA’s OSIRIS-REx.
For more information: Carbonaceous chondrite meteorites experienced fluid flow within the past million years