A new Star will arrive in the Solar System in a few years

An astronomer predicted that our Sun could have many more encounters with other stars than we thought, which could have major implications for life on Earth.


Coryn Bailer-Jones of the Max Planck Institute for Astronomy in Germany used data from ESA's Gaia satellite to monitor the movement of more than 300,000 stars. With that, he modeled how a total number of 1 billion stars in our galaxy can move over time.

He found that our Sun experiences "close" encounters with between 490 and 600 stars every million years. Some passing 16.3 light years away, while others, much closer and potentially harmful, 6.5 light years away.


(You must be thinking now: What about Proxima Centauri? Correct, it is a shorter distance than that predicted by the astronomer, but remember: they are considerably smaller in mass than other stars expected to find our Sun) .


The danger is that a passing star could disturb the Oort cloud, a region of comets thought to extend up to a light year from our Sun. If the star is big enough, or gets close enough, it could send comets towards us, potentially causing extinction-level events.


"What's interesting is that, since the rate of encounters is quite high, there are probably many comets launched into the Solar System all the time," said Bailer-Jones. “What if a massive star near the end of its life arrived nearby and was a supernova? This could have happened in the past, we have evidence of nearby supernovae leaving marks on Earth, “he concluded.


Don't be too scared, because (yet) there is no evidence of impending encounters that could end life on Earth. Bailer-Jones says the risk of impacts from close-to-Earth objects (NEOs) like asteroids remains much greater.


But in about 1.3 million years, a dwarf star called Gliese 710 is expected to come very close to Earth. Previous estimates suggest it will only be about 1 light year away. The Gaia data, however, suggests that this will be much closer, perhaps only about a quarter of a light-year away, or 16,000 times the Earth-Sun distance. This is well within the predicted region of the Oort cloud.


Whether close encounters with other stars really have an effect on our Solar System is unclear. Some theories suggest that passing stars could have been responsible for extinction events on Earth, such as impacts from comets or asteroids. We still don't have direct evidence for that.


It is interesting to note, however, that the estimate of about 87 close encounters every million years extends to the past, as well as the future. It is likely, therefore, that we had many old visitors. [ IFLS ]

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