PSK RESEARCH
Main Menu => Science, Astronomy, & Physics => Topic started by: Psk on February 20, 2015, 04:38:57 PM
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Seventy thousand years ago, when humans were migrating from Africa and before Neanderthals became exstinct, an alien star flew through the outer reaches of the solar system.
Passing less than a light-year from Earth, it was the closest stellar near-miss known so far.
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.
When scientists computed the past orbit "Scholz's star", they found that it came within 0.8 light-years of Earth. That is within the outer reaches of the Oort cloud, a faraway realm populated by trillions of comets.
The Oort cloud is host to an enormous number of comets, some of which visit the inner solar system regularly. But many more of these comets would have come flying towards earth if a passing star-were to approach and perturb the cloud.
A hailstorm of comets could have catastrophic consequences for life on Earth, so astronomers hope to figure out how common these close encounters are. It doesn't look like we have to worry soon. The next closest stellar approach is forecast to be between 240,000 and 470,000 years from now, and should avoid the Oort cloud.