Earth's ancient water mystery: Enstatite chondrites hold clues
The latest findings by scientists suggest that Earth may have had water from the very beginning, not solely from cosmic collisions. This discovery could revolutionize our understanding of planet formation.
Researchers have found that meteorites similar to those that contributed to early Earth's formation might contain hydrogen in the form of hydrogen sulfide. This suggests that our planet could have formed from materials already containing elements necessary to create water. The study results were published in the scientific journal "Icarus".
Earth may have had water from the beginning
Earth shares a chemical composition with anhydrous rocky bodies known as enstatite chondrites. For years, scientists believed water must have come from objects in the outer Solar System that bombarded Earth. However, research from 2020 indicated that enstatite chondrites contain hydrogen, which could have reacted with oxygen on early Earth to form water. The study's lead author, James Bryson from the University of Oxford, and his team suspected that hydrogen might have been bonded with sulfur in these meteorites.
The researchers used X-ray absorption spectroscopy to detect traces of hydrogen bonded with sulfur in an enstatite chondrite found in Antarctica in 2012. They discovered more hydrogen than expected, existing as hydrogen sulfide, which suggests that Earth might have contained hydrogen since its formation. "The abundant hydrogen indicates that Earth could have contained hydrogen since the planet’s formation," Bryson wrote in an email to Live Science.
Additional hydrogen could have come from Antarctic ice
However, not all scientists are convinced. Conel Alexander, a scientist at the Carnegie Institution for Science in Washington, notes that these chondrites might be contaminated with Earth's existing water. "When they enter the Earth's atmosphere and see water and even oxygen, they're going to start reacting quite quickly," he told Live Science. Additional hydrogen could have originated from Antarctic ice and melted water surrounding the meteorite before its discovery.
Although researchers attempted to avoid studying areas visibly affected by water, the latest chondrite could eventually confirm the origin of hydrogen. "The perfect thing would be for a sample of an enstatite chondrite to fall to Earth, and we scoop it up immediately and stick it into a water-free, oxygen-free environment and keep it there," added Alexander.
