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

Curtin College-led analysis into the sturdiness and age of an historical asteroid made from rocky rubble and dust, revealed vital findings that might contribute to doubtlessly saving the planet if one ever hurtled towards Earth.

The worldwide group studied three tiny dust particles collected from the floor of historical 500-meter-long rubble pile asteroid, Itokawa, returned to Earth by the Japanese Area Company’s Hayabusa 1 probe.

The examine’s outcomes confirmed asteroid Itokawa, which is 2 million kilometers from Earth and across the measurement of Sydney Harbor Bridge, was exhausting to destroy and immune to collision.

Lead creator Professor Fred Jourdan, Director of the Western Australian Argon Isotope Facility, a part of the John de Laeter Centre and the College of Earth and Planetary Sciences at Curtin, stated the group additionally discovered Itokawa is sort of as outdated because the solar system itself.

“In contrast to monolithic asteroids, Itokawa will not be a single lump of rock, however belongs to the rubble pile household which implies it is solely made from free boulders and rocks, with nearly half of it being empty space,” Professor Jourdan stated.

“The survival time of monolithic asteroids the dimensions of Itokawa is predicted to be solely a number of lots of of hundreds of years within the asteroid belt.

“The massive influence that destroyed Itokawa’s monolithic guardian asteroid and fashioned Itokawa occurred no less than 4.2 billion years in the past. Such an astonishingly lengthy survival time for an asteroid the dimensions of Itokawa is attributed to the shock-absorbent nature of rubble pile materials.

“In brief, we discovered that Itokawa is sort of a big space cushion, and really exhausting to destroy.”

The Curtin-led group used two complementary strategies to research the three dust particles. The primary one known as Electron Backscattered Diffraction and might measure if a rock has been shocked by any meteor influence. The second methodology—argon-argon relationship—is used to this point asteroid impacts.

Co-author Affiliate Professor Nick Timms, additionally from Curtin’s College of Earth and Planetary Sciences, stated the sturdiness of rubble pile asteroids was beforehand unknown, jeopardizing the flexibility to design protection methods in case one was hurtling towards Earth.

“We got down to reply whether or not rubble pile asteroids are immune to being shocked or whether or not they fragment on the slightest knock,” Affiliate Professor Timms stated.

“Now that we’ve discovered they will survive within the solar system for nearly its complete historical past, they have to be extra plentiful within the asteroid belt than beforehand thought, so there’s extra probability that if a giant asteroid is hurtling towards Earth, will probably be a rubble pile.

“The excellent news is that we will additionally use this data to our benefit—if an asteroid is detected too late for a kinetic push, we will then doubtlessly use a extra aggressive strategy like utilizing the shockwave of a close-by nuclear blast to push a rubble-pile asteroid off track with out destroying it.”

Curtin College co-authors embody Affiliate Professor William Rickard, Celia Mayers, Professor Steven Reddy, Dr. David Saxey and John Curtin Distinguished Professor Phil Bland, all from the College of Earth and Planetary Sciences.

Printed within the Proceedings of the Nationwide Academy of Sciences, the examine is titled “Rubble pile asteroids are endlessly.”