Natural History Museum: Ancestral asteroid reveals secrets of our solar system


New chemical analyses of the asteroid Ryugu has concluded that its make up is similar to that of our Sun. The samples, some of the most pristine ever collected, have led scientists to believe that the asteroid formed within 5 million years of the birth of our solar system.

A sample of Ryugu weighing just 5g was collected from the asteroid and brought to Earth by Japan's Hayabusa2 space probe in 2020. Since then, teams around the world have been working on the small amount of sand and dust in a global effort to unlock its secrets. What makes the samples so special is that they were collected in space directly from the Ryugu asteroid and have remained un- contaminated.

Prof Sara Russell, Senior Research Lead at the Natural History Museum and an author on the new paper said, 'This research marks a huge success and proof of concept for collecting samples from asteroids in space. It reminds me of Sir Walter Raleigh bringing back a potato from the Americas!

When meteorites fall to earth, they instantly become contaminated by our atmosphere and later by the surroundings in which they land. The samples that have been collected by Hayabusa2 are pristine and uncontaminated meaning we can say with confidence that what we find when analysing the chemistry of Ryugu is what is present in the asteroid.'

Metorites that fall to earth often act like a sponge soaking up water and compromising their composition. This means that examples like the Ivuna meteorite which fell to earth in Tanzania in 1938 have a far higher percentage of water present than they likely would have had as an asteroid in space.

Further analysis of the samples collected hope to reveal more about how the asteroid formed and in doing so unlock the secrets of how our solar system formed.

Prof Sara Russell concludes, 'Understanding the chemical makeup of asteroids like Ryugu is essential to our understanding of how our solar system formed.

'The initial analysis of Ryugu shows strong similarities to meteorites like Ivuna, which shows that we can use our meteorite collection here at the Natural History Museum and the data we have collected on meteorites to feed into space mission results.

'Due to Ryugu's composition we now effectively have a better baseline of what the solar system is made up of. This will allow us to track changes through time and understand better the process by which solar systems are formed and age.'

The paper Samples returned from the asteroid Ryugu are similar to Ivuna-type carbonaceous meteorites is published in the journal Science.

Press Release