I suspect everyone has heard that we recorded the largest gamma-ray burst humanity has ever witnessed. Of course, since we haven't had much time in observing them, that alone doesn't mean a whole lot. But it was enormous compared to everything else we have seen.
And we are very lucky it was so far away. Anything like that in our half of the Milky Way and we could be in a world of hurt. From a Facebook group I belong to:
It is pretty incredible to consider an event that could kill almost all life within something like 20,000 lightyears.
A newly-observed Gamma-ray burst might be the brightest space explosion ever seen
One group of scientists refers to its as the "BOAT", or "Brightest Of All Time."
interestingengineering.com
And we are very lucky it was so far away. Anything like that in our half of the Milky Way and we could be in a world of hurt. From a Facebook group I belong to:
Fortunately for us this event wasn't in our galaxy. If this GRB would have happened in "our side" of the Milky Way galaxy our atmosphere would have immediately turned dark red as the gamma rays quickly depleted much of the Earth's protective ozone layer, allowing an increase in solar UVB radiation to reach the surface and most life on Earth would be either dead or dying. For the "typical" nearest GRBs in the last billion years, global average ozone depletion up to 38% and localized depletion up to 74% occurred. This radiation damages DNA many times normal (well above lethal levels for simple life forms like phytoplankton) and causes severe sunburns to humans. In addition, NO2 produced in the atmosphere would have caused a decrease in visible sunlight reaching the surface, Nitric acid rain would stress portions of the biosphere, and the entire Earth would be heading into a long massive global deep freeze (for thousands of years).
Any life within a few tens of thousands of light years of this GRB was likely destroyed.
It is pretty incredible to consider an event that could kill almost all life within something like 20,000 lightyears.