Interstellar travel is not for humans as the timescale is well beyond a human lifespan , but celestial bodies , such as asteroids and comet , can move from hotshot scheme to star system . Humanity has find two such objects already : Comet Borisovand‘Oumuamua , which crossed the vast gulf of infinite for a agile foray across the Solar System . We do not experience where they do from , but researchers have wondered what the hazard is that our close star organization is send objects to us .

Alpha Centauri is a ternary - ace arrangement , with one of its star , Proxima Centauri , being the literal nigh star to the Sun at 4.25 wakeful - years away . Such star systems are not come together off ; stars have a great gravitational sphere of influence , but some objects can be easily distributed in a way that sends them flying to another star . What ’s play is that the Alpha Centauri organisation isgetting closerto the Sun , moving at 22 kilometre per 2d ( 49,000 mi per hour ) . In about 28,000 years , it will be at its closest – just three light - years away – before moving aside again .

The law of proximity and the approach make Alpha Centauri a outstanding font study for the spread of interstellar objects . That is why Cole Gregg and Paul Wiegert from the University of Western Ontario have estimated just how many of its space rocks might have reached our corner of the universe , and it is an telling number .

Let ’s consider the outer region of the Solar System : the Oort swarm . This is a cloud ofcometsand asteroids that might extend to 1.5 light - eld aside from the Sun . If the Alpha Centauri organisation loses as many aim as the Solar System does , then within the Oort cloud , Gregg and Wiegert calculate that there are about one million interstellar objects larger than 100 meters ( 330 feet ) that have been place over by our neighbour .

To reword theFermi Paradox , where are they all then ? The account is that these objects are small , and the world is massive . The mass of one of these objects comparedto the whole Oort cloudis like the volume of a white blood cell compared to the sizing of the Sun . The chance of incur one of these object within the orbit of Saturn is tiny , one in a million .

The good newsworthiness is that the Solar System becomes an easier target as Alpha Centauri gets closer . As such , we are to probable to receive more of its interstellar object – up to 10 times as many during close approach . We might still discover more interstellar objects , as the Solar System could crossone million watercourse of them . However , if we desire something from Alpha Centauri , we require to think smaller .

If the size parameters are drop to anything larger than 100 micrometer ( like a thick human tomentum ) , then the estimation shoots up . In exceptional , among the many meteors that shower down the Earth every year , about 10 of them are from Alpha Centauri . This too will increase by a factor of 10 .

“ A thoroughgoing understanding of the mechanisms by which material could be transferred from [ Alpha ] Centauri to the Solar System not only compound our knowledge of interstellar ecstasy but also opens new pathways for research the interconnection of stellar system and the potential for material substitution across the Galaxy , ” the generator wrote in thepaper .

The paper has been accepted for publication in The Planetary Science Journal and a preprint version is uncommitted onarXiv .