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NASA Spacecraft Solves Decades-Old Mystery of Juno Lightning

NASA has solved the mystery of lightning on Jupiter, which has long puzzled researchers.

Lightning bolts on Jupiter didn’t appear to generate the same high-energy radio emissions that accompany discharges on Earth, confounding scientists.

However, the Juno spacecraft was recently able to get close enough to Jupiter to confirm that the bolts do in fact give off similar emissions to the bolts on Earth.

The findings are detailed in two new papers, and were made possible, researchers said, because the Juno craft was able to get closer to Jupiter than any probe ever had previously.

“No matter what planet you’re on, lightning bolts act like radio transmitters—sending out radio waves when they flash across a sky,” said Shannon Brown of NASA’s Jet Propulsion Laboratory in Pasadena, California, a Juno scientist and lead author of one paper.

“But until Juno, all the lightning signals recorded by spacecraft [Voyagers 1 and 2, Galileo, Cassini] were limited to either visual detections or from the kilohertz range of the radio spectrum, despite a search for signals in the megahertz range. Many theories were offered up to explain it, but no one theory could ever get traction as the answer.”

However, there are key differences between the lightning on Jupiter and Earth, such as the fact most activity happens on Jupiter near the poles while most activity on Earth is near the equator.

“Jupiter lightning distribution is inside out relative to Earth,” said Brown. “There is a lot of activity near Jupiter’s poles but none near the equator. You can ask anybody who lives in the tropics—this doesn’t hold true for our planet.”

Video Credit: GeoBeats