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Safe Neighborhood
StarDate:
July 27, 2021Our planet appears to be in one of the safest neighborhoods in the Milky Way Galaxy. We’re away from the regions where deadly exploding stars are most common.
That’s the finding of a study released this year. Researchers in Italy looked at the number of supernovas and gamma-ray bursts over the entire history of the galaxy.
A supernova is the death of a star. It fills its region of space with radiation and particles. They can sterilize nearby planets, and be harmful at distances of dozens of light-years. A gamma-ray burst is also an exploding star. But it emits powerful beams from its poles that can zap life thousands of light-years away.
The researchers found that early on, the safest region of the Milky Way was its rim, far beyond Earth. There were fewer exploding stars out there. Earth’s region, about halfway out to the edge, was a little more dangerous.
Over time, though, the “safe” zone moved inward. And over the last half-billion years, we’ve been at the outer edge of that zone. There have been more supernovas closer to the center, and more gamma-ray bursts out on the rim.
In the future, the number of exploding stars in our neighborhood should keep going down — making it even safer.
The Milky Way arches across the eastern evening sky now. The center of the galaxy is in the south, above the “spout” of the teapot formed by the stars of Sagittarius. That’s the galaxy’s danger zone — a neighborhood to avoid.
