How close to Earth would a supernova need to be before it caused significant damage to our ecosystem?
A few years ago, there was a theory that perhaps the dinosaurs were killed off by the effects of an explosion of a nearby star. This theory has been more recently supplanted by the idea of a giant asteroid impact doing the deed, but the exploding star theory did spur some interest. This question comes up occasionally here (you are not the first!), so some of the folks here put together a very good synopsis of the results of a nearby supernova (SN), or exploding star. In turn, I will give a synopsis of their results. Supernovae are very bright, and they put out light at all different wavelengths. Different wavelengths do different damage; for example, ultraviolet light can directly cause skin damage (even cancer), while infrared does relatively little damage. Certainly x-rays can wreak havoc as well! But before we panic, let’s look at the numbers. First, let’s note that the nearest star that can explode is probably the star Betelgeuse in the constellation of Orion. Distance estimates to
