The meteorite that fell in the English countryside last year is the most pristine ever seen
A meteorite that lit up the sky over an English village last year is almost as pristine as samples collected by space probes and contains the “right” kind of hydrogen to explain Earth’s water, scientists say.
A great furore broke out when a a fireball thundered across the evening sky over SW England on 28 Feb 2021. Dozens meteor bell cameras and webcams spotted the bright streak and a 1 pound (0.5 kilogram) fragment of the space rock was promptly found in the driveway of a house in the village of Winchcombe, after which the meteorite was later named.
The quick discovery meant that the meteorite was barely exposed to Earth’s elements, allowing it to retain its pristine chemical composition. In fact, the composition of the Winchcombe meteorite is so pristine that it can almost match samples collected by space probes such as NASA’s OSIRIS-REx from asteroids in space, researchers said in a new study.
Connected: How scientists found rare pieces of a fireball meteorite in a driveway and what they can teach us
Analysis of this precious rock has produced fascinating results that seem to support the theory that The Earthwater mostly comes from asteroids. The Winchcombe space rock contains hydrogen atoms with an isotopic composition quite similar to that of water on Earth. Isotopes are varieties of the same chemical elements that differ in the number of neutrons in their atomic nuclei. Other possible sources of water on Earth, such as cometswere found to contain water with different isotopic profiles.
The analysis also found that the meteorite must have broken away from its parent asteroid relatively recently in the cosmic scheme of things — just 200,000 to 300,000 years ago. Most meteorites, the scientists say in the paper, spend millions of years in interplanetary space before their paths cross those of Earth, during which time they are ravaged by cosmic rays and sunny wind.
By analyzing data from cameras that captured the Winchcombe meteorite cruise through Earth’s atmosphereastronomers were able to reconstruct the rock’s orbit and determine that its parent asteroid was located in main asteroid belt between the orbits of Mars and Jupiter and not among the near-Earth asteroid population.
The Winchcombe meteorite is a carbonaceous chondritea rare class of meteorites believed to come from very primitive asteroids that migrated into the main asteroid belt from the outer edges of solar system. Scientists believe that the chemical composition of these asteroids has hardly changed since the birth of the Solar System. And that means that thanks to its pristine nature, the Winchcombe meteorite provides a unique view into these ancient ‘time capsules’.
In addition to the right kinds of hydrogen, the meteorite also contained organic material of the kind that could have created life on Earth about 3.5 billion years ago, scientists said in statement (opens in new tab).
All in all, the Winchcombe meteorite was a very lucky strike.
“Direct connections between carbonaceous chondrites and their parent bodies in the Solar System are rare,” the scientists said in the paper. “The Winchcombe meteorite is the most precisely recorded fall of a carbonaceous chondrite.”
Only four journeys of carbonaceous chondrites through the Earth’s atmosphere have so far been observed well enough to determine their origin. Most of the others found “are chance finds that lack information about their source in the solar system,” the researchers said in the paper.
Learning (opens in new tab) describing the first analysis of this precious rock was published Nov. 16 in the journal Science Advances.
Follow Teresa Pultarova on Twitter @TerezaPultarova. Follow us on Twitter @Spacedotcom and on Facebook.
#meteorite #fell #English #countryside #year #pristine
