European space scientists are planning to put special cameras on board the International Space Station (ISS) to take a closer look at the phenomenon of giant lightning.
The different types of giant lightning go by exotic names: red sprites, blue jets and elves. Instead of striking downwards, from the clouds to the ground, it flashes upwards, with some discharges being so large that they reach the border between the atmosphere and space.
Little is known about the giant lightning flashes, mainly because they are all but invisible from the ground. One hypothesis is that they actually alter the chemical composition of the atmosphere, thus playing a role in ozone depletion and the climate on Earth.
"The question is how are these giant flashes of lightning created and how often do they take place", says senior scientist Torben Neubert, head of the project at Danish National Space Centre. "We need to understand the natural processes which influence the atmosphere and this can help us decide which changes in the climate are man-made."
To find out, the European Space Agency (ESA) has asked Danish researchers to study a package of instruments called Atmosphere-Space Interactions Monitor. These are designed to operate from the ISS, and will provide data on how giant lightning affects the atmosphere.
The space shuttle Columbia was gathering data on the flashes during its last mission. Some scientists suggest that the shuttle was actually struck by a huge upwards flash of lightning on re-entering the atmosphere, and that this was the cause of its destruction.
NASA does estimate that on average one in a hundred shuttle missions would be affected by the electrical phenomenon, but says that it was not the cause of Columbia's break-up.
ESA says it is still to early to say when the cameras will actually be deployed. ®