Seen in the infrared, Jupiter looks like a slowly spinning molten sphere, crisscrossed by rings of fire and swirling conflagrations. Of course, that’s not how the solar system’s largest planet actually looks—it’s a chilly, gassy world with a big red pockmark and multi-coloured bands of clouds—but that’s the view the Juno spacecraft’s aurora-mapping instrument just sent back to Earth.
Juno arrived at Jupiter on July 4, when the craft endured a heart-stopping manoeuvre to safely orbit the giant world. But it took a few weeks for Juno to send pictures back to Earth, because instruments that has been sleeping during the make-or-break orbit insertion needed to be fired back up while Juno dropped into a more snuggly orbit.
Included in the early postcards from the Jupiter-orbiting spacecraft are the first views of the planet’s North Pole, snapped from orbit on August 27. As it turns out, that pole is not at all what scientists had expected. Notably absent are the characteristic cloudy bands that snake their way around the planet at lower latitudes, as well as any geometrically shaped storms, likethe hexagon on Saturn’s North Pole.
Instead, cloud shadows are visible on the planet’s northern cap, which is bluer than expected and sprinkled with a number of small, circular storms. While swooping over the stormy pole, Juno also detected the eerie sounds of radio waves produced by the charged particles responsible for Jupiter’s massive auroras—emanations that have been known about since the 1950s but which have not been studied up close until now.
"Jupiter is talking to us in a way only gas-giant worlds can," Bill Kurth, a Juno co-investigator from the University of Iowa, said in a statement.
In infrared wavelengths, Jupiter's southern pole resembles a raging inferno [Image: NASA, JPL-CALTECH, SWRI, MSSS]
This is just the first of 36 orbits Juno will be making as it studies Jupiter over the next two years, and these early results already suggest that the massive world has a few surprises in store.
That in itself is hardly surprising. These last decades of solar system exploration have repeatedly shown us that getting to know these worlds is a bit like getting to know a person: Becoming truly acquainted with a planet, moon, or any of the celestial bodies orbiting our sun is impossible unless we take the time and make the effort to go there and see them up close.