Sprites and Trolls at the Edge of Space

This is pretty cool [emphasis added]

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 onboard the International Space Station were perfectly positioned to observe red sprites dancing atop a cluster of storms in Mexico. 

A few minutes after the astronauts saw the sprites, they spotted a related creature–a “Troll.” It jumped up to the left of the sprites: [see image above]

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
[…]
“Trolls are also known as ‘secondary transient luminous events,” explains Oscar van der Velde, a member of the Lightning Research Group at the Universitat Politècnica de Catalunya. “They are occasionally observed alongside big clusters of sprites, and they can reach 40-60 km high.”

Van der Velde says that sprites can actually pull Earth’s ionosphere down toward the thunderstorm. When the gap shrinks, and the local electric field intensifies, Trolls appear.

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For the full story and more pictures visit SpaceWeather