NASA-led firefly mission to study lightning

November 15, 2013

Somewhere on Earth, there's always 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. 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.

"Gamma rays are thought to be emitted by electrons traveling at or near the speed of light when they're slowed down by interactions with atoms in the upper atmosphere," said Therese Moretto Jorgensen, program director in NSF's Division of Atmospheric and Geospace Sciences, which funds Firefly. "TGFs are among our atmosphere's most interesting phenomena."

The electrons needed to create gamma rays have to be moving so fast and carrying so much energy, that scientists were at a loss to explain what process near Earth could kick them up to such high speeds. Indeed, prior to the discovery of TGFs, scientists thought electrons moving this fast could only be generated near much larger bodies such as stars, galaxies or black holes.

Lightning by itself is thought to be only a tenth as strong as would be needed to accelerate the electron beams to such incredible speeds, but scientists have hypothesized that perhaps some lightning is triggered by an electron avalanche, a runaway chain reaction that pushes electrons up to these incredible speeds. Understanding the mechanism for what accelerates the electron beams near Earth will help scientists understand how the same process happens throughout the rest of the universe.

"The idea that some of the lightning overhead may be triggered by the same processes that happen in supernovas and cosmic particle accelerators is mind-blowing," said Rowland. "I've never looked at thunderstorms the same way since learning about these ideas."

The NSF CubeSat program represents a low cost access to space approach to performing high-quality, highly targeted science on a smaller budget than is typical of more comprehensive satellite projects, which have price tags starting at $100 million. The CubeSat Firefly, by focusing its science goals, will carry out its mission in a much smaller package and at a considerably lower cost.

The Firefly mission also emphasizes student involvement as part of the ongoing effort to train the next generation of scientists and engineers. Students at Siena College, in Loudonville, N.Y., and the University of Maryland Eastern Shore, in Princess Anne, Md., were involved in all phases of the Firefly mission.

The window for Firefly launch opens on Nov. 19, 2013, and it is scheduled to launch with 27 other cubesat missions, as well as a NASA experiment called the Total solar irradiance Calibration Transfer Experiment, or TCTE, which will continue measurements from space of the total energy output of the sun.
Karen C. Fox
NASA's Goddard Space Flight Center, Greenbelt, Md.

NASA/Goddard Space Flight Center

Related Gamma Rays Articles from Brightsurf:

Properties of catalysts studied with gamma ray resonance
Steam-assisted oil extraction methods for heavy deposits have long been the focus of attention at Kazan Federal University.

Strange gamma-ray heartbeat puzzles scientists
Scientists have detected a mysterious gamma-ray heartbeat coming from a cosmic gas cloud.

Physicists find ways to control gamma radiation
Researchers from Kazan Federal University, Texas A&M University and Institute of Applied Physics (Russian Academy of Sciences) found ways to direct high frequency gamma radiation by means of acoustics.

Excess neutrinos and missing gamma rays?
A new model points to the coronoe of supermassive black holes at the cores of active galaxies to help explain the excess neutrinos observed by the IceCube Neutrino Observatory.

APS tip sheet: correlating matter's distribution in the universe with gamma rays
Scientists present the first direct cross-correlation between dark matter and gamma ray emissions.

APS tip sheet: High energy gamma rays
Nine Galactic sources are the highest-energy gamma -ray sources ever detected, which could suggest the presence of Galactic accelerators.

First detection of gamma-ray burst afterglow in very-high-energy gamma light
An international team of researchers observe a gamma-ray burst, an extremely energetic flash following a cosmological cataclysm, emitting very-high-energy gamma-rays long after the initial explosion.

Gamma-ray bursts with record energy
The strongest explosions in the universe produce even more energetic radiation than previously known: Using specialised telescopes, two international teams have registered the highest energy gamma rays ever measured from so-called gamma-ray bursts, reaching about 100 billion times as much energy as visible light.

Hubble studies gamma-ray burst with highest energy ever seen
NASA's Hubble Space Telescope has given astronomers a peek at the location of the most energetic outburst ever seen in the universe -- a blast of gamma-rays a trillion times more powerful than visible light.

The highest energy gamma rays discovered by the Tibet ASgamma experiment
The Tibet ASgamma experiment, a China-Japan joint research project, has discovered the highest energy cosmic gamma rays ever observed from an astrophysical source - in this case, the 'Crab Nebula.' The experiment detected gamma rays ranging from > 100 Teraelectron volts (TeV) to an estimated 450 TeV.

Read More: Gamma Rays News and Gamma Rays Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to