'Clumped' asteroids nearly impossible to destroy, study suggests

‘Clumped’ asteroids nearly impossible to destroy, study suggests

Asteroid Itokawa. Credit: Curtin University

Curtin University-led research into the durability and age of an ancient asteroid made of rocky debris and dust has revealed significant findings that could help potentially save the planet if one were ever to crash into Earth.


The international team studied three tiny dust particles collected from the surface of the 500-meter-long ancient debris asteroid Itokawa, returned to Earth by the Japanese Space Agency’s Hayabusa 1 probe.

The results of the study showed that the Itokawa asteroid, which is 2 million kilometers from Earth and about the size of the Sydney Harbor Bridge, was hard to destroy and resistant to collisions.

Lead author Professor Fred Jourdan, director of the Western Australian Argon Isotope Facility, part of the John de Laeter Center and the Curtin School of Earth and Planetary Sciences, said the team also found that Itokawa is almost as as old as the solar system itself.

“Unlike monolithic asteroids, Itokawa is not a single lump of rock, but belongs to the debris pile family, meaning it is made up entirely of boulders and loose rocks, with almost half being empty space,” Professor Jourdan said.

“The survival time of monolithic asteroids the size of Itokawa is estimated to be only a few hundred thousand years in the asteroid belt.

“The giant impact that destroyed Itokawa’s monolithic parent asteroid and formed Itokawa happened at least 4.2 billion years ago. Such an astonishingly long survival time for an asteroid the size of Itokawa is attributed to the shock-absorbing nature of the debris pile material.

“In short, we found that Itokawa is like a giant space cushion and very hard to destroy.”

Discoveries of asteroids from bits of space dust could save the planet

Itokawa granules with scale. Credit: Celia Mayers / Curtin University

Curtin’s team used two complementary techniques to analyze the three dust particles. The first is called Electron Backscatter Diffraction and can measure whether a rock has been shocked by a meteorite impact. The second method – argon-argon dating – is used to date asteroid impacts.

Co-author Associate Professor Nick Timms, also from Curtin’s School of Earth and Planetary Sciences, said the durability of debris pile asteroids was previously unknown, jeopardizing the ability to design defense strategies should one head for Earth.

“We set out to answer whether debris pile asteroids are shock-resistant or fragment at the slightest impact,” Associate Professor Timms said.

“Now that we’ve found they can survive in the solar system for most of its history, they must be more abundant in the asteroid belt than previously thought, so there’s a better chance that if a large asteroid is headed for Earth, it will be. a pile of rubble.

“The good news is that we can use this information to our advantage – if an asteroid is detected too late for a kinetic push, then we can use a more aggressive approach, such as using the shock wave of a nearby nuclear explosion to push. a debris pile asteroid moves the course without destroying it.”

Co-authors from Curtin University include Associate Professor William Rickard, Celia Mayers, Professor Steven Reddy, Dr David Saxey and John Curtin Distinguished Professor Phil Bland, all from the School of Planetary and Earth Sciences.

Published in Proceedings of the National Academy of Sciencesthe study is titled “Asteroids in the Debris Pile Are Forever.”

More information:
Jourdan, Fred, asteroids in the debris pile are forever, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2214353120.

Provided by Curtin University

Citation: ‘Rubble pile’ asteroids nearly impossible to destroy, study suggests (2023, January 23) Retrieved January 24, 2023, from https://phys.org/news/2023-01-rubble-pile-asteroids-impossible-destroy. html

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