Welcome to this week’s AITN Lite and we are talking about an article from quite a while ago. Last week’s AITN bulletin discussed the returning of a sample from an asteroid. This week is about an asteroid that is potentially hazardous to Earth. The article can be found here:
A sample was returned from the asteroid Itokawa and those particles were analysed. This asteroid is considered a rubble pile asteroid. They consist of reassembled fragments from larger asteroids that have collided and shattered. The gravitational pull of the constituent parts, made up of fragments of all sizes, keeps them. The analysis found that the Argon isotope ratio, which can be used as a dating technique, gave an age of 4.2 billion years.
This age is comparable with that of the Solar System itself, aged at 4.57 billion years. As such, over that time, it would have been subject to many collisions, and yet it has survived. Compared to a more solid, monolithic asteroid, this is a much longer timescale. These solid asteroids have a lifespan of hundreds of millions of years, a factor of 10 shorter. The conclusion that can be made from this is that these rubble pile asteroids are harder to destroy and, as such, are much more abundant in the Solar System than previously thought, and this may influence the way we would deflect one that was on a direct path towards Earth.
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