A team of scientists from the University of Oxford has found evidence that water on Earth is not derived from asteroids, contrary to a long-held theory. The researchers used ultra-powerful X-rays to analyze space rocks from the early days of our solar system, which date back about 4.5 billion years.
The study focused on an enstatite chondrite meteorite found in Antarctica, which contained high levels of hydrogen sulphide – a compound that was already present within the asteroid itself. This suggests that water on Earth was created naturally through the interaction of hydrogen with oxygen-containing compounds in the magma oceans.
According to Dr James Bryson, associate professor at the university’s department of Earth sciences, “The material that built our planet was far richer in hydrogen than we thought previously.” The finding supports the idea that the formation of water on Earth was a natural process, rather than a result of hydrated asteroids impacting the planet after it formed.
In 2022, a meteorite discovered in Gloucestershire contained water resembling Earth’s water, but this study suggests that by the time the early Earth became large enough to be struck by asteroids, it would have already accumulated sufficient hydrogen reserves to explain its present-day water abundance. This discovery has significant implications for searching for life on other planets and suggests that habitable conditions may not rely solely on space rocks.
Source: https://www.telegraph.co.uk/news/2025/04/15/water-did-not-come-earth-from-asteroids-oxford-study