Do you ever wonder how the “bumps” in the path of the Sun affect our weather? Probably not, and it certainly is not the leading story in the evening weather report. To the credit of meteorologists, this is because the Sun rarely does come across any “bumps,” or side effects of near collisions with other stars.
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From time to time the Sun will approach very closely to other stars in its orbit around the Milky Way. By “close” we mean that another star will pass within about three light-years of the Sun, which for reference is less than the distance between the Sun and the nearest star.
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For example, a close passage of the Sun with another star 65 million years ago may have shaken loose several of the trillions of comets surrounding our solar system. Some of these “freed” comets would be sent hurtling into the inner solar system, where one of them could strike the Earth. In this scenario, on that one fateful day, the aftermath of the giant impact killed the dinosaurs.
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Today, astronomers are able to search for new stars that may invoke other “doomsday” cometary showers, thanks to results arriving from the GAIA satellite. GAIA is a ne satellite that specializes in making exquisite measurements of star positions.
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A team led by astronomer Bailer-Jones from the Max Planck Institute computed stellar orbits for 7 million stars.
They find that 25 stars will make closes approaches with the Sun within the next five million years. In fact, one of them, Gliese 710, is expected to hit that same repository of comets that led to the dinosaur’s doom in 1.3 million years.
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Just how close this star will come to us will determine when/if there will be another “perfect storm” which could lead to a new wave of extinction on Earth. Let’s hope not…
