Scientists freeze image of 64 km long lightning bolt

These rarely seen, highly charged meteorological events are known as gigantic jets, and they flash up to the lower levels of space, or ionosphere.
While they don't occur every time there is lightning, they are much larger than their downward striking cousins.
"Despite poor viewing conditions as a result of a full moon and a hazy atmosphere, we were able to clearly capture the gigantic jet," said study leader Steven Cummer, electrical and computer engineer at Duke University in North Carolina (DUNC).
Images of gigantic jets have only been recorded on five occasions since 2001.
The Duke University team caught a one-second view and magnetic field measurements that are now giving scientists a much clearer understanding of these rare events.
"This confirmation of visible electric discharges extending from the top of a storm to the edge of the ionosphere provides an important new window on processes in earth's global electrical circuit," said Brad Smull, programme director of the National Science Foundation (NSF) division of atmospheric sciences, which funded the research.
It appears from the measurements that the amount of electricity discharged by conventional lightning and gigantic jets is comparable, Cummer said.
But the gigantic jets travel farther and faster than conventional lightning because thinner air between the clouds and ionosphere provides less resistance.
Cummer caught the gigantic jet almost by accident. The equipment had been set to capture another phenomenon known as sprites, which were first photographed in 1989, said a DUNC release.
Sprites are electrical discharges that occur above storm clouds and are red or blue, with jellyfish-like tendrils hanging down.
These findings appeared online in Nature Geoscience.