What we're the odd aurora-looking explosions I saw in the sky?

It matters the time of the year. But the answer was most likely meteorites. When they plummet to earth, they cause disturbances in the atmosphere, and in a chain reaction, disturbances in the magnetic field, causing the aurora to form a shock wave pattern were the meteorites entered the atmosphere. A meteor show may have been going on, causing all of different shock waves. Nothing to worry about, because the Aurora is beautiful. :)