When an aurora takes place, the Earth's atmosphere grows upwards around the aurora. If a spacecraft travels through this region, then it slows down slightly (like driving a car through mud).

The problem is that a spacecraft needs to travel above a certain speed to stay in its orbit. As it slows down, it will start to fall towards Earth. This is what happened to Skylab.

Skylab was the first American manned space station (the USSR had the first space station, called Salyut, in 1971), and it flew during 1973-1977. It ended up falling out of the sky, and nobody was exactly sure where it would land!

Because it weighed 75 tonnes, there was a worry that it may cause a lot of damage and perhaps kill people. In the end, though, nobody was injured, but there were a few holes left in Australia!