Sounds of the Aurora Borealis...

For years scientists believed that reports of sounds accompanying the aurora borealis were mistaken, or possibly the result of too much alcohol (this was actually posited as a cause!).  But then some scientists heard them, when not drunk.  Oops.  So then they had to figure out where the sound actually came from, because the lights of the aurora borealis are clearly too far away to hear.  Now they have: the sounds come from just 70 meters (about 220 feet) above the ground...