Seventy thousand years ago, when modern humans were on the verge of migrating from Africa and before Neanderthals died out, an alien star flew through the outer reaches of the solar system.

Passing less than a light-year from Earth, the flyby was the closest stellar near-miss identified so far, scientists reported Tuesday in Astrophysical Journal Letters.

Ordinarily too dim for human eyes to perceive, the small red dwarf may have flared up during its extremely close brush with Earth, making it visible to early humans if they chanced to look skyward at the right moment.

When scientists reconstructed the past orbit of the star, known as Scholz's star, they found that it once came within 0.8 light-years (roughly eight trillion kilometers) of