Somewhere across the Earth each day and night, there's a lightning flash. The globe experiences lightning some 50 times a second, yet the details of what initiates this common occurrence and what effects it has on the atmosphere – lightning may be linked to incredibly powerful and energetic bursts called terrestrial gamma ray flashes, or TGFs—remains a mystery.
Credit: Zina Deretsky, National Science Foundation
In mid-November, a football-sized mission called Firefly, which is funded by the National Science Foundation, will launch into space to study lightning and these gamma ray flashes from above.
The Firefly instrument is what's known as a cubesat, a very small satellite that offers the chance for quality space science with a relatively inexpensive price tag.
"We can do great science with these small missions," said Doug Rowland, the principal investigator for Firefly at NASA's Goddard Space Flight Center in Greenbelt, Md.
"Firefly will gather up to a year of observations on the mysterious workings of lightning. Lightning is so familiar we tend to take it for granted, but we really don't know the details of how it works—even though it is a critical part of the global electric circuit, and has obvious social and technological effects."
Lightning is ubiquitous and intimately connected to life on Earth, but we don't often think about what's happening higher up in the atmosphere.
The radiation generated by lightning is so intense that it can generate antimatter and gamma rays within TGFs just a few miles of the ground.
NASA's Compton Gamma Ray Observatory first discovered TGFs in the 1990s. Designed to look outward at cosmic sources of gamma rays, the mission also caught rare but tantalizing glimpses of gamma rays coming from Earth.
Firefly's mission is to study the relationship between lightning and huge bursts of gamma rays called terrestrial gamma ray flashes.
Credit: NASA/Goddard Space Flight Center
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