4.6 billion-year-old meteorite confirms the theory of the origin of water on Earth

A 4.6 billion year old space rock landed in front of an ordinary house in the English city of Winchcombe in February 2021. It was registered by special meteor cameras. The fireball was also filmed by numerous home and car DVR systems, and there were over 1,000 eyewitness accounts of the fall and reports of the sound of the impact .

The main part of the meteorite   (319.5 g) was discovered the day after the fall. The rock fell into the driveway, shattering into pieces, both of which, and the dust from the fall, were collected just 12 hours after the event.

The largest intact piece of the Winchcomb meteorite is a 152g melt-crusted rock found on farmland in March 2021. In total, scientists received 531.5 g of material for research.

The space rock is a carbonaceous chondrite, a rare carbon-rich type of meteorite. Direct links between carbonaceous chondrites that have fallen to Earth and their “parent” bodies in the solar system are rarely observed. The Winchcombe meteorite is currently considered the most accurately recorded fall of a carbonaceous chondrite. Its exoatmospheric orbit and cosmic-ray age confirm that it arrived on Earth shortly after being ejected from a primitive asteroid. 

Since the stone was found only a few hours after it crashed into the Earth, it practically did not change under the influence of the earth’s environment. In addition, the composition of the meteorite was also restored a few hours after the fall. This greatly simplifies the analysis and study of the stone, and in fact, scientists can use it to “look” at the original composition of the solar system.

To analyze the minerals and elements within the rock, the researchers ground, heated, and irradiated the rock with X-rays and lasers. So they figured out that the meteorite came from an asteroid in orbit around Jupiter .

But most importantly, according to the analysis, the meteorite contains water, which is very similar in chemical composition to water on Earth. Thanks to this, scientists have found confirmation of the theory of how our planet was seeded with a life-giving substance.

When the rocky planets of the young solar system first formed from hot clouds of gas and dust , they were too close to the central star . Because of this, the ice from their surfaces evaporated, which turned the young Earth into a barren and inhospitable object. The hypothesis suggested that everything changed after the Earth cooled. It happened when a shower of icy asteroids brought frozen water to our planet . 

Now, a new analysis of the Winchcomb meteorite, published in Science Advances , has confirmed that theory. The almost intact hydrogen isotopic composition of the Winchcomb meteorite is comparable to that of Earth’s hydrosphere, and 11% of the meteorite’s mass is water.

Hydrogen in the water of the asteroid was in two forms: ordinary hydrogen and an isotope of hydrogen – deuterium . It turned out that the ratio of hydrogen and deuterium is the same as in water on Earth. This is very convincing evidence that the water in the stone and the water on our planet have a common origin.

It was also possible to determine that the stone contains a large amount of hydrated silicates formed during fluid-rock reactions, as well as carbon – and nitrogen-containing organic substances, including soluble protein amino acids – the building blocks for proteins involved in the formation of life.

To further confirm the theory, other rocks around the solar system can also be analyzed.