About a million “macroscopic” objects originating from our nearest star system, Alpha Centauri, may already be in the Oort cloud. That’s what the results of a new study show.
So far, scientists have found only two confirmed interstellar objects in the Solar System: the unusually elongated object Oumuamua, about the nature of which there is still debate, and the comet Borisov. Both celestial bodies have disappeared from the field of view of Earth’s telescopes long ago. But velocity and trajectory analysis allowed us to prove their interstellar origin.
However, scientists have long suspected that there are actually many other undetected interstellar objects passing through the Solar System every year. An even larger number were probably captured by the Sun’s gravity and became part of its permanent “population”. This is indicated by data from several missions, including the now-defunct Cassini, which have been able to detect tiny particles of interstellar dust.
In a new study published on the arXiv preprint server, scientists have modeled how much interstellar material has been ejected from our nearest star system, Alpha Centauri, over the past 100 million years. Based on these numbers, they calculated that there should be about a million “macroscopic” objects from Alpha Centauri within our Solar System at this time. We are talking about bodies whose dimensions exceed 100 meters.
Unlike Oumuamua and Comet Borisov, these interstellar “immigrants” were permanently captured by solar gravity. Most of them are likely now in the Oort cloud, a giant reservoir of comets and asteroids at the edge of the Solar System. As a result, they are almost impossible to detect.
As for smaller objects, scientists have calculated that theoretically any particles larger than 100 micrometers can travel between systems. About 10 such particles probably burn up in the Earth’s atmosphere as meteors each year. Alpha Centauri is currently moving toward us and will reach its closest point to the Sun in about 28,000 years. When this happens, the number of objects in the Solar System will increase exponentially for a while, as the distance between the two systems will be greatly reduced.
As for the Solar System, its material ejection rate is probably very similar to Alpha Centauri. This means that neighboring star systems probably capture a comparable number of objects originating from our cosmic neighborhood.
According to Livescience.com
