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Scientists find source of rarest meteorite to fall on Earth - 84 years later!

MeteoriteImage source, Trustees of the National History Museum

UK scientists believe they have identified the source of the Ivuna meteorite - one of the rarest to ever fall on Earth.

It landed in Tanzania in December 1938 and was split into a number of samples, one of which is now at the Natural History Museum (NHM) in London.

Now 84 years later, experts from the museum believe the rock may have come from the edge of the solar system.

They made the discovery following analysis of an asteroid known as Ryugu, which was made possible after samples of it were brought back to Earth in 2020.

The team said its findings could unlock more answers about the early history of the solar system and shed more light on how life came to exist on Earth.

Professor Sara Russell, a senior research lead at the museum, helped to write the paper and said it was a really exciting discovery.

[This discovery] shows that meteorites in our museum and in collections around the world, might actually sample most of the solid solar system, from the innermost rocky part to its furthest outer reaches.

— Professor Sara Russell, Expert from Natural History Museum

She said the research can be used by the team to help them learn more about the solar system as well as other planets.

The Ivuna falls into a category of extremely rare meteorites known as CI chondrites.

These are stony carbon-containing meteorites whose chemistry shows they have been around since the formation of the solar system more than four billion years ago.

They have been known to contain water - one of the key ingredients to life.

Media caption,

Space probe bites asteroid

Professor Russell said that apart from Ivuna, only four other known CI-type meteorites exist on Earth: Orgueil and Alais, which both fell in France, Tonk which fell in India, and the tiny Revelstoke meteorite which fell in Canada.

She said: "It's only within the last decade we've begun to appreciate just how far objects in the solar system can move towards and away from the Sun."

For the study, the team examined Ryugu samples, which were remotely brought back to Earth by Japanese spacecraft Hayabusa2.

Professor Russell said: "By comparing the forms of iron in both the asteroids and meteorites, we learnt that Ryugu is a remarkably close match to CI chondrites."

Image source, JAXA
Image caption,

Japanese spacecraft Hayabusa2

It is thought that Ryugu, which is classed as a near-Earth object, was born in the outer solar system more than four billion years ago and broke away from a larger body, moving towards Earth.

It is now found between the Earth and Mars and orbits the Sun.

Ryugu belongs to a class of asteroids called carbonaceous, or C-type, asteroids - rich in water, carbon and organic compounds from when the solar system formed.

The researchers said both Ryugu and the CI chondrites seem to come from the same region of space - the outskirts of the solar system.

They think they might be even more closely related, sharing the same parent body.