Scientists Think Visitors From Another Star System May Have Infiltrated Our Galactic Neighborhood

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Scientists Think Visitors From Another Star System May Have Infiltrated Our Galactic Neighborhood

Alpha Centauri is the star system closest to our Solar System, and it is likely that particles from it could be making their way over to or already be in our stellar neighborhood.

To know what to expect, researchers used existing models to predict how many particles of different sizes may already exist in the Solar System and are possibly coming in from Alpha Centauri every year.

Studying the ejection and transfer of particles from Alpha Centauri could tell us more about how material is exchanged between star systems.

While interstellar objects (

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, anyone?) have passed through our

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before, the origins of many of these objects remain unknown. Did they originate in a nearby

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system? A distant one? A completely different galaxy?

Unfortunately, it’s not currently possible to track ‘Oumuamua down for further study. Its

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will take it too far for any spacecraft to reach or any telescope to observe. But that doesn’t mean we have no interstellar subjects available for study—in fact, it turns out we have plenty of particles from another star system already here.

The closest stellar system to us is the triple system

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. It’s currently creeping closer to our Solar System at 79,000 km per hour (about 49,709 mph), and should be at its closest around 27,700 years from now. With that in mind, researchers Cole Gregg and Paul Wiegert from the University of Western Ontario decided to see how many Alpha Centauri objects might have made it to us already, and how many could eventually make it here in the future.

“A small number [less than 10 meteors] may currently be entering Earth’s atmosphere every year,” Gregg and Wiegert said in a study soon to be published in the

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, “[and] is expected to increase as Alpha Centauri approaches.”

Alpha Centauri is a mature star system, at 5 billion years old. This means that most of the material in this system’s protoplanetary disk has likely already dissipated, so it is not expected to release much debris out into space (though there might be material from the system in our asteroid belt and our distant

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). That said, the gravitational forces of more stars and planets make it more likely for material to scatter, and there may be planets orbiting its three stars (though, none have yet been confirmed).

To find out if Alpha Centauri could be currently ejecting material, the researchers turned to existing models of how star systems usually eject debris. The models predicted that, despite the small number of objects from Alpha Centauri that are expected to make it all the way to

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every year, there could be as many as a million over-one-hundred-meter-in-diameter-sized objects from the system already lurking in our Oort cloud (many smaller object and particles may also be among them).

The problem is that the Oort cloud is on the outer edge of the Solar System. This would make potential Alpha Centauri objects—if they really are somewhere in there—difficult to observe. Though, it wouldn’t be impossible. NASA’s New Horizons Mission has a dust detector actively

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in the Kuiper belt that might have been leftovers from the formation of our Solar System. The Oort cloud is even further out, but despite a dwindling fuel supply,

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may be able to hold on long enough to get out there and scan for the presence of something from Alpha Centauri.

That said, the presence of these objects is not certain. There is also the issue of smaller particles from Alpha Centauri potentially not surviving the journey to the Solar System. They could be deflected by

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, slow down significantly due to drag in the interstellar medium, or end up decimated by extremely fast gas atoms or collisions with each other.

For any particles that do survive and manage to enter the inner Solar System, the

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’s gravity will increase their velocity significantly. Even more particles could come from hypothetical comets—at least, they could if Alpha Centauri ejects as many as our Solar System—but these are unlikely to be observed. Whether these potential particles are actually detectable remains to be seen.

“A thorough understanding of the mechanisms by which material could be transferred from Alpha Centauri to the Solar System not only deepens our knowledge of interstellar transport,” the researchers said in the same study, “but also opens new pathways for exploring the interconnectedness of stellar systems and the potential for material exchange across the

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