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takyon [soylentnews.org] writes:

The interstellar asteroid 'Oumuamua's likely movements have been tracked [theconversation.com] based on the relative positions of nearby stars. Observations of 'Oumuamua [wikipedia.org] indicate that it has only been subjected to interstellar conditions (cosmic rays, gas, dust) for hundreds of millions of years rather than billions. There are likely to be around 46 million such interstellar objects entering the solar system every year, most of which are too far away to be seen with current telescopes, and are quickly ejected:

[My (Fabo Feng)] latest study [arxiv.org] gives us a glimpse of exactly where 'Oumuamua may have come from. Reconstructing the object's motion, my research suggests it probably came from the nearby "Pleiades moving group" of young stars, also known as the "Local Association". It was likely ejected from its home solar system and sent out to travel interstellar space.

Based on 'Oumuamua's trajectory, I simulated how it has probably travelled through the galaxy and compared this to the motions of nearby stars. I found the object passed 109 stars within a distance of 16 light years. It went by five of these stars from in the Local Association (a group of young stars likely to have formed together), at a very slow speed relative to their movement.

It's likely that when 'Oumuamua was first ejected into space, it was travelling at just enough speed to break away from the gravity of its planet or star of origin, rather than at a much faster speed that would require even more energy. This means we'd expect the object to move relatively slowly at the start of its interstellar journey, and so its slow encounters with these five stars suggests it was ejected from one of the group.

Pleiades star cluster [wikipedia.org]. "Codes and results" [github.com] for the arXiv paper.

We should capture as many interstellar asteroids as possible and smash them together to create a new dwarf planet near the Earth.

Previously: Possible Interstellar Asteroid/Comet Enters Solar System [soylentnews.org]
Interstellar Asteroid Named: Oumuamua [soylentnews.org]
ESO Observations Show First Interstellar Asteroid is Like Nothing Seen Before [soylentnews.org]
Breakthrough Listen to Observe Interstellar Asteroid 'Oumuamua for Radio Emissions [soylentnews.org] (none were found)

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