Extraterrestrial water was first found in a meteorite that fell in the UK.
The Winchcombe meteorite, which crashed into a driveway in the Gloucestershire town last February, is also thought to contain clues to where the water came from in Earth’s vast oceans.
Ashley King, a researcher with the planetary materials group at the Natural History Museum, said 12 percent of the sample was water and, being the least contaminated specimen to collect, offers plenty of insight.
He told the British Science Festival: “The composition of that water is very, very similar to the composition of the water in Earth’s oceans.
“It’s really good proof that asteroids and bodies like Winchcombe have made a very important contribution to the Earth’s oceans.”
Dr King also confirmed that Winchcombe was the first time a meteorite containing extraterrestrial water, albeit encased in minerals, has fallen in the UK.
He added that due to how quickly the 0.5 kg (1 pound) meteorite was recovered, within about 12 hours, it was not contaminated by water and materials on Earth.
He said: “We always try to match the composition of water meteorites and other extraterrestrial materials to the composition of water on Earth.
“For most of the meteorites the challenge we have is that they are simply contaminated, whereas with Winchcombe we really know it wasn’t really contaminated, so that’s good evidence.”
Dr. King continued: “One of the big questions we have in planetary sciences is where does water come from on Earth? And one of the most obvious places is through comets that contain loads and loads of ice, or asteroids.
“There is always a debate: were comets the main source, were asteroids the main source?”
Explaining that the data from missions to comets suggests they are not a good match for water on Earth, he added: “The composition of water in Winchcombe is a much better match, so this would imply that the asteroids – carbonaceous asteroids – were probably the main source of water for the inner solar system, for the Earth.
Dr. King continued: “We have had a clue that some asteroids match well with the Earth.
“But now we have a really cool meteorite that we know hasn’t been modified and is confirming the same story.”
Speaking at De Montfort University, which hosts the festival, Dr. King said the analysis revealed that the meteorite came from an asteroid somewhere close to Jupiter.
It was formed about 4.6 billion years ago, with its journey to Earth about 300,000 years.
There are approximately 65,000 known meteorites on Earth.
This is the first known carbonaceous chondrite to be found in the UK and the first meteorite recovered in the UK in 30 years.