Research suggests that tiny specks of dust from a “giant space pillow” as old as the solar system could provide new clues about how to avoid a catastrophic asteroid strike.
Three tiny particles of dust — smaller than the diameter of a hair — collected from a 500-meter asteroid known as Itokawa show that some of these space rocks are much older and more solid than previously thought.
Classified as a potentially dangerous asteroid, the peanut-like Itokawa could veer dangerously close to Earth and could cause significant damage if it collided.
A study published in the Proceedings of the National Academy of Sciences found that Itokawa formed more than 4.2 billion years ago, making it more than 10 times older than solid asteroids of similar size. In contrast, the solar system is 4.57 billion years old.
Itokawa is a rubble-pile asteroid, which forms when solid asteroids collide and the resulting fragments coalesce into new structures. It consists of rocks, dust, gravel and emptiness, held together by the gravity of its various components.
Solid asteroids are believed to be hundreds of millions of years old, and are gradually being receded by constant collisions.
“This long asteroid survival time is attributed to the shock-absorbing nature of the rubble piles’ material, and suggests that rubble piles are difficult to destroy once established,” the study authors wrote.
“We were really surprised,” said Professor Fred Jordan of Curtin University’s School of Earth and Planetary Sciences, first author of the study. “This is really, really old, and I’m sure some of my colleagues won’t believe it.”
“It’s like a giant space pillow, and the pillows are really good at absorbing shock,” Jordan told AFP.
The asteroids that make up the rubble mound are highly resilient to the constant blows they face, and are likely to be much more abundant than previously assumed. Jordan said this could mean we need new ways to deal with such asteroids on a collision course with Earth.
NASA’s recent Dart test showed that asteroids like Itokawa can be pushed off course, but this could take several years out.
An asteroid just weeks after hitting Earth would require a different approach, and Jordan says a nuclear blast might be needed if an asteroid is detected too late to deflect a direct impact.
“It’s not Armageddon-style,” he says, “it’s blowing it up,” a reference to the 1998 sci-fi movie. The shock wave should push the asteroid out of the way. [without destroying it]. “
It’s a far-reaching conclusion to be drawn from such tiny specks of dust, but every particle is analyzed at the atomic level.
The team analyzed the crystal structures in the samples, looking for distortions caused by the impact that caused Itokawa. They dated the samples by measuring the decomposition of potassium into argon.
“We can get great stories like this from [something] “Very, very small,” Jordan said, “because these machines, what they do, is measure and count atoms.” “Each bean has its own story to tell.”
The three samples of Itokawa dust were originally collected by the Japan Space Agency’s Hayabusa 1 probe in 2005.
The samples were returned to Earth five years later. Scientists have been analyzing it, along with hundreds of other particles from Itokawa, for clues ever since.
– with AFP
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