Research led by Fred Jordan of Curtin University (Australia) into the life and age of the “messy” asteroid Itokawa has provided important findings that could save our planet if such an object were ever to head towards Earth. Jordan and his colleagues come to this conclusion after analyzing three tiny dust particles collected and brought back to Earth by the Japanese space probe Hayabusa 1 20 years ago (Proceedings of the National Academy of SciencesJanuary 23).

Research results show that it would be difficult to destroy Itogawa, which is about five hundred meters long, even at a distance of two million kilometers from Earth. That’s because it’s not a solid rock, but a so-called “vacuum asteroid” – a loose mass of rock and dust, almost half of which is empty space.

In the asteroid belt between Mars and Jupiter, massive Itokawa-sized asteroids have an expected lifetime of only a few hundred thousand years. Decay asteroids are thought to be the remnants of large asteroids that were destroyed in collisions with each other, after which some of their fragments reassembled. For Itogawa, that would have happened at least 4.2 billion years ago. It follows Radiometric dating Argon isotopes found in asteroid dust particles.

Apparently, such junk asteroids are more resistant to maneuvering collisions, but it is not clear why. New research indicates that the reason lies in the shock-absorbing properties of the debris they contain. Like cosmic airbags, they can hit one after the other. According to researchers, there are more such objects floating around in the asteroid belt than previously thought.

This also means that if a large asteroid ever hits Earth, it is more likely to be a junk asteroid. According to Jordan and his colleagues, this is good news for both Earth and the asteroid. If the latter is discovered too late, he should be thrown out A space probe like DART, which can always be done with the help of a nuclear explosion. A ‘built-in’ airbag ensures that the object remains intact. (EE)

Asteroid discoveries could save the planet from specks of space dust