A team of international researchers discovered evidence of recent water movement in meteorites that recently impacted Earth. The researchers looked at the carbon chondrite (CC) meteorites that have affected the planet’s surface over the past 100 years. Finding evidence of modern water movement is important because many scientists believe that the water on Earth came from meteorites.
Scientists who share This theory They had a hard time proving this because the meteorites so far found do not contain water. Contributed to the difficulty in proving the theory that chemical reactions that would have involved water transported by comets occurred millions of years ago. For the new research, the team took a different approach to trying to prove the theory that involves studying isotopes in meteorites that have affected Earth over the past century.
Previous research indicates that all of the CC meteors formed about 4.5 billion years ago as part of larger asteroids. The team studied the distribution of uranium and thorium in the meteorite samples. Uranium is soluble in water, while thorium is insoluble. The researchers assumed that if water had been present in the meteorite, it would have moved as it melted. The movement is reflected in the isotope distribution of thorium and uranium.
Both isotopes also have short half-lives, so if their distributions could be found in meteorites, it would happen relatively late on a cosmic scale in the order of a few million years. The researchers studied nine meteorites, and the team found the distributions they were looking for, indicating that the water was moving due to possible melting over the past million years.
The team believes that this type of meteorite could have delivered water to Earth during our planet’s formation years. The idea could be tested by taking samples of asteroids before they hit Earth, such as those that JAXA collected recently and returned to Earth.