Astronomers have been intrigued at the notion of lightning strikes on Jupiter since Voyager 1 detected flashes nearly four decades ago, notes Space.com. Now the Juno orbiter has revealed a surprise: Those strikes are more similar to lightning strikes on Earth than previously thought. For one thing, Jupiter's lightning can strike at the same rate as lightning on Earth—Juno's more sensitive equipment picked up about six times more strikes than Voyager did, detecting up to four lightning strokes per second, reports Gizmodo. And while Voyager and subsequent NASA spacecraft detected strikes only in the relatively low-frequency kilohertz range, Juno has revealed that Jupiter also has strikes in the higher-frequency megahertz and gigahertz ranges, just like Earth.
"Given the very pronounced differences in the atmospheres between Jupiter and Earth, one might say the similarities we see in their thunderstorms are rather astounding," the University of Iowa's William Kurth, co-author of one of two new studies in Nature, tells Space.com. But Juno also revealed a key difference in the two planets, regarding where the strikes occur. "There is a lot of activity near Jupiter’s poles but none near the equator," says NASA scientist Shannon Brown in a release. "You can ask anybody who lives in the tropics—this doesn’t hold true for our planet." Among the things to be resolved: why the strikes occur so often at the north pole in particular. Juno has been orbiting Jupiter since 2016, and it will make its 13th flyby over the planet's clouds on July 16. (Juno provided the best look yet at Jupiter's "red spot.")