Tag: Supernova

Earth's protective atmosphere has protected life for billions of years, creating an environment for evolution to produce complex life forms like us. The ozone layer plays an important role in protecting the biosphere from deadly UV rays. Block 99% of the sun's powerful UV rays. Earth's magnetosphere also protects us. But the Sun is relatively interesting. How effectively does the ozone and magnetosphere protect us from powerful supernova explosions? Every million years - a tiny fraction of Earth's 4.5 billion years - a giant star explodes within 100 parsecs (326 light years) of Earth. We know this because our solar system exists in a space called the local bubble. A cavernous space where the density of hydrogen is lower than outside the bubble. During the previous 10-20 million ye...