‘Rubble pile’ asteroids nearly impossible to destroy, study suggests

A Curtin University-led study of the durability and age of an ancient asteroid made of rocky debris and dust has revealed an important discovery that could save our planet if it lunges towards us.

An international team studied three tiny dust particles collected from the surface of the asteroid Itokawa, a 500-meter-long ancient rubble mound brought back to Earth by the Japanese space agency’s Hayabusa 1 probe.

The results of this study showed that the asteroid Itokawa, which is about the size of the Sydney Harbor Bridge and is located 2 million kilometers from Earth, is hard to destroy and hard to collide with.

Lead author Professor Fred Jordan, part of the John de Reiter Center and director of the Argon Isotope Facility in Western Australia, part of Curtin’s School of Earth and Planetary Sciences, said the team also: He said he discovered that Itokawa is almost as old as the solar system itself.

“Unlike monolithic asteroids, Itokawa is not a single boulder, but belongs to the rubble mountain family, which means it is made entirely of loose rocks and boulders, and nearly half of it is empty space.” said Professor Jordan.

“A monolithic asteroid the size of Itokawa is predicted to survive in space for only a few hundred thousand years. asteroid belt.

“The giant impact that destroyed Itokawa’s monolithic parent asteroid and formed Itokawa occurred at least 4.2 billion years ago. It is caused by absorbability.

“In short, Itokawa is like a giant cosmic cushion, and it turned out to be very difficult to destroy.”

Curtin and his team analyzed three dust particles using two complementary techniques. The first one, called electron backscatter diffraction, can measure whether a rock has been impacted by a meteorite impact. A second method, argon-argon dating, is used to date asteroid impacts.

Nick Timms, also an associate professor in the Department of Earth and Planetary Sciences at Curtin University, said the durability of asteroids, mountains of rubble, was previously unknown, jeopardizing the ability to design defensive strategies should they rush toward Earth. He said he was exposed.

“We set out to find out if a pile of rubble could withstand impact, or whether it would break apart at the slightest impact,” Tims said.

“Now that we know it can survive for almost the entire history of the solar system, it should be more abundant in the asteroid belt than previously thought. So if a large asteroid is flying toward Earth, it’s going to be a lot of debris.” Mountain.

“The good news is that we can use this information to our advantage. If an asteroid is detected too late for a dynamic push, we could use a more aggressive approach, such as using the shock wave of a nearby nuclear explosion to push.” There is an asteroid in a pile of rubble that veers off course without destroying it.”

Curtin University co-authors include Associate Professor William Ricardo, Professor Celia Meyers, Professor Stephen Reddy, Dr. David Saxey, and John Curtin Distinguished Professor Phil Brand of the Department of Earth and Planetary Sciences.

Posted in Proceedings of the National Academy of Sciencesthe study is titled “Rubble Mountain Asteroids Forever”.