A bit of space news. Tuesday, two satellites collided in Earth orbit, completely destroying each other in the process. This is a relatively rare phenomenon which could have disastrous consequences.
You see, even though there are thousands of artificial satellites orbiting the Earth, its still pretty much empty space. There may be, on average, tens or hundreds of miles between satellites most of the time. But, given enough time, satellites will collide and produce a lot of debris. Satellites are often maneuvered in order to avoid just this type of scenario, but even so, this still happened.
But what is the danger? A bunch of satellite shrapnel raining down on Earth isn’t much to be worried about as the vast majority of it will burn up in the atmosphere. The real danger lies in the fact that pieces of an exploding satellite can impact other satellites, which then create even more debris, which impacts even more satellites in a runaway chain reaction. The result? Low Earth orbit becomes completely filled with debris, making sending any more satellites (and crewed expeditions) impossible. As soon as they reach orbit, they would be obliterated by debris. Such a situation could cut off access to space for centuries.
To be honest, I don’t think a single event like this could cause this. But increase the number of events, and the number of satellites orbiting, and you could have a real problem.