We all know what comes out of the bottom of thunderclouds: lightning. But rarely do we see what comes out of the top. On August 10th, astronauts on board the International Space Station were perfectly positioned to observe red sprites dancing atop a cluster of storms in Mexico. They snapped this incredible photo (above).
This shows just how high sprites can go. The photo shows their red forms reaching all the way from the thunderstorm below to a layer of green airglow some 100 km above Earth’s surface. This means sprites touch the edge of space, alongside auroras, meteors and noctilucent clouds. They are a true space weather phenomenon.
A few minutes after the astronauts saw the sprites, they spotted a related creature–a “Troll.” …