About 70,000 years ago
A red dwarf known as Scholz’s star passed through the edge of our solar system less than a lightyear away from the sun about 70,000 years ago, according to a new paper.
In the paper, published in the journal The Astrophysical Journal Letters, scientists write that they believe the Scholz’s star and its brown dwarf companion passed through the far part of our solar system called the outer Oort Cloud. There is no other known star that has come so close.
The scientists who spotted it needed to determine whether it was coming toward the solar system or flying away from it. Through their calculations, they were able to determine that the star is 20 light years away, BBC reports, and that it passed the solar system and is heading away. They estimated the flyby likely happened around 70,000 years ago.
There were concerns that the star could have affected with the gravitational orbits of the comets that reside in the Oort Cloud, but researchers concluded that its impact was “negligible.”