Looks like you're using an older browser. For the best experience possible, please upgrade your browser or download a modern browser.
We recommend these free browsers: Firefox or Chrome
You must update your Flash version to view videos. http://www.adobe.com/go/getflashplayer
For the optimal Juno experience please install Chrome. Download Chrome. Or continue to explore features of the Juno spacecraft using the links on your left.




Ever since NASA’s Voyager 1 spacecraft flew past Jupiter in March, 1979, scientists have wondered about the origin of Jupiter’s lightning. That encounter confirmed the existence of Jovian lightning, which had been theorized for centuries. But when the venerable explorer hurtled by, the data showed that the lightning-associated radio signals didn’t match the details of the radio signals produced by lightning here at Earth.

In a new paper published in Nature today, scientists from NASA’s Juno mission describe the ways in which lightning on Jupiter is actually analogous to Earth’s lightning. Although, in some ways, the two types of lightning are polar opposites.

“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 the 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.”

Enter Juno, which has been orbiting Jupiter since July 4, 2016. Among its suite of highly sensitive instruments is the Microwave Radiometer Instrument (MWR), which records emissions from the gas giant across a wide spectrum of frequencies.  

“In the data from our first eight flybys, Juno’s MWR detected 377 lightning discharges,” said Brown. “They were recorded in the megahertz as well as gigahertz range, which is what you can find with terrestrial lightning emissions. We think the reason we are the only ones who can see it is because Juno is flying closer to the lighting than ever before, and we are searching at a radio frequency that passes easily through Jupiter’s ionosphere.”

While the revelation showed how Jupiter lightning is similar to Earth’s, the new paper also notes that where these lightning bolts flash on each planet is actually quite different.

“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.”

Why do lightning bolts congregate near the equator on Earth and near the poles on Jupiter? Follow the heat.

Earth’s derives the vast majority of its heat externally from solar radiation, courtesy of our Sun. Because our equator bears the brunt of this sunshine, warm moist air rises (through convection) more freely there, which fuels towering thunderstorms that produce lightning.

Jupiter’s orbit is five times farther from the Sun than Earth’s orbit, which means that the giant planet receives 25 times less sunlight than Earth. But even though Jupiter’s atmosphere derives the majority of its heat from within the planet itself, this doesn’t render the Sun’s rays irrelevant. They do provide some warmth, heating up Jupiter’s equator more than the poles -- just as they heat up Earth. Scientists believe that this heating at Jupiter’s equator is just enough to create stability in the upper atmosphere, inhibiting the rise of warm air from within. The poles, which do not have this upper-level warmth and therefore no atmospheric stability, allow warm gases from Jupiter’s interior to rise, driving convection and therefore creating the ingredients for lightning.

“These findings could help to improve our understanding of the composition, circulation and energy flows on Jupiter,” said Brown. But another question looms, she said. “Even though we see lightning near both poles, why is it mostly recorded at Jupiter’s north pole?”

In a second Juno lightning paper published today in Nature Astronomy, Ivana Kolmašová of the Czech Academy of Sciences, Prague, and colleagues, present the largest database of lightning-generated low-frequency radio emissions around Jupiter (whistlers) to date. The data set of more than 1,600 signals, collected by Juno’s Waves instrument, is almost 10 times the number recorded by Voyager 1. Juno detected peak rates of four lightning strikes per second (similar to the rates observed in thunderstorms on Earth) which is six times higher than the peak values detected by Voyager 1.

“These discoveries could only happen with Juno,” said Scott Bolton, principal investigator of Juno from the Southwest Research Institute, San Antonio. “Our unique orbit allows our spacecraft to fly closer to Jupiter than any other spacecraft in history, so the signal strength of what the planet is radiating out is a thousand times stronger. Also, our microwave and plasma wave instruments are state-of-the-art, allowing us to pick out even weak lightning signals from the cacophony of radio emissions from Jupiter. “

NASA's Juno spacecraft will make its 13th science flyby over Jupiter's mysterious cloud tops on July 16.

NASA's Jet Propulsion Laboratory, Pasadena, California, manages the Juno mission for the principal investigator, Scott Bolton, of the Southwest Research Institute in San Antonio. Juno is part of NASA's New Frontiers Program, which is managed at NASA's Marshall Space Flight Center in Huntsville, Alabama, for NASA's Science Mission Directorate. The Microwave Radiometer instrument (MWR) was built by JPL. The Juno Waves instrument was provided by the University of Iowa. Lockheed Martin Space, Denver, built the spacecraft.
NEW! Skechers Men's SKECH FLEX LIFE FORCE Shoes Navy/Black g dz,DC ~ Men's White Leather Slip On Shoes Slides Skater Skate Board Athletic~ 9,Blue on Blue Nike SB Paul Rodriguez - worn twice!!!,Nike Free Trainer 3.0 Men's Gray Athletic Running Shoes 553684-002 Size 11,ASICS JB Elite V 2.0 Wrestling Shoes J501N-9099 Black/Onyx Jordan Burroughs SZ8,adidas Pureboost DPR - Red Running, Cross Training (Men's 11.5) - Used,Glow in the Dark Women's Mens Casual Shoes Justin Bieber High Top Canvas Shoes #,Alpine Swiss Josef Men Tennis Shoes Low Top Sneakers Flex Strap Mesh Knit CollarASICS GEL-Saga Soft Grey Blue Men’s Athletic Running Shoes Sz 12Paul Sperry Mens Sojourn Plain Toe Grey Shoes Sneakers 8M,$69.99 $60 Converse Men Sumner Ox gray parchment white black 151398C,Men's/Women's USED Jordan 6 Chrome Size 14 Beautiful design Quality and quantity guaranteed comfortable,$130 Saucony Mens Omni 16 Running Sneaker Shoes, Grey/Navy/Orange, US 12 W,Men's Basketball Shoes Athletic Sneakers Fashion Outdoor Performance Sport ShoesBoombah Metal Spikes / Cleats SVM2 Low Black and Maroon - Size 12New! Men's Skechers Relaxed Fit Glides Kenton Casual Shoes 65011 Navy pc 18J,SAUCONY PROGRID HURRICANE 11 RUNNING SHOES sz 9.5 20026-3-9.5 MENS,FILA Travail Men's Trail Shoes brown sz 13,Adidas Mens White Baseball Cleats Size 8.5 (10269),MENS OPEN BACK SHOES 13D Heavy duty & well made. Very comfortable.,Vans Off the Wall Alomar MTE Brown Antique Suede Mens 8.5 Shoes Hi Top,Men’s Fashion Casual Sneakers Running Athletic Sports Breathable Shoes Big Size,Men's Mesh Lightweight Athletic Shoes Casual Sneakers Breathable Running Jogging$119.99 ALIFE Everybody Mid Parachute Nylon (navy) SU9EVMO2,Mens Nike INCENERATE Size: 8.5 Black white,US Shoe Size Men Slip On Light Comfort Athletic Casual Sneakers Walking BlackFilament F151007/004 - Hypha - Athletic Sneakers Woodpecker - Size:10.5 B,Fila F-13V FB Syn Suede VF059FX 022 Black Hi Top Sneaker Men SZ 7.5 - 11,Canaan Dog Running Shoes For Men-Free Shipping,Adidas Mens - Black Running Shoes Size 11 (310822),
Franklin Sz: 8 US, 7.5 UK, 41 Euro Men's Vintage Cleats in Red,

Members of the media, please contact:

D.C. Agle
Juno Media Relations Representative
NASA's Jet Propulsion Laboratory
Dwayne Brown
NASA Public Affairs Officer
NASA Headquarters

Where is Juno now?

Visualize Juno’s journey through space and get up-to-date data sets using NASA's Eyes on the Solar System 3D interactive.