How did meteorite impacts on the Moon influence water being delivered to Earth when both planetary bodies were forming? This is what a recent study published in the Proceedings of the National Academy of Sciences hopes to address as a team of researchers investigated whether water-rich meteorites were responsible for delivering water to Earth during the late stages of the latter’s formation. This study has the potential to help scientists better understand the processes for life existing on our planet and could help gain insights into how life might form on other worlds.
For the study, the researchers analyzed lunar regolith Apollo samples with the goal of gaining insight into the elements that meteorite impacts delivered to the Moon billions of years ago. The reason the researchers chose to analyze lunar regolith is because Earth’s surface history is constantly being erased due to plate tectonics and weathering processes, meaning impacts from billions of years ago have long been covered or returned to beneath the surface. In the end, the researchers identified oxygen isotope “fingerprints” to determine that the amount of water delivered to the Earth by water-rich meteorites was very small compared to the water delivered to the Moon.
“The main takeaway from our study is that Earth’s water budget is hard, if not impossible, to explain if we only consider a single, late delivery pathway from water-rich impactors from the outer solar system,” said Dr. Tony Gargano, who is a postdoctoral fellow at the Lunar and Planetary Institute and lead author of the study. “Even though some meteorite types carry a lot of water, their broader chemical and isotopic fingerprints are quite exotic relative to Earth. Habitability models have to satisfy such empirical constraints, and our study adds a constraint that future theories will need to reproduce.”
Lead author, Dr. Tony Gargano, seen in the University of New Mexico's Center for Stable Isotopes. (Credit: University of New Mexico)
What new insight into how water was delivered to Earth will researchers make in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!
Sources: Proceedings of the National Academy of Sciences, EurekAlert!
