Blast from exploding stars trapped Earth in "space bubble", NASA says
NASA has found evidence that a nearby cluster of the explosions "went off like popcorn", blowing an enormous bubble into space - which we are still inside.
Supernova explosions are terrifyingly powerful - in a split second, a star tears itself apart, and more energy is released than the sun shines out in a million years.
Supernova explosions happen on average once every 50 years in our galaxy - making the exploding star outshine the entire Milky Way for a brief moment. A new NASA X-ray experiment has found evidence of a barrage of relatively recent explosions near Earth - and a strange "bubble" created around us.
Astronomers today scan for nearby stars likely to explode: were a Type II supernova to occur within 26 light years of Earth, the blast of gamma rays would shred the ozone layer, leaving creatures on Earth exposed to deadly cosmic rays.
https://uk.news.yahoo.com/blast-from-exploding-stars-trapped-earth-in-%E2%80%9Cspace-bubble%E2%80%9D--nasa-says-115918572.html