Nearly two months after entering an orbit around Jupiter, NASA's Juno probe has finally gotten close enough to provide a few spectacular — and unprecedented — images of the massive planet's polar regions. On Aug. 27, the probe completed its first close flyby (about 2,500 miles above Jupiter's cloud tops) with all of its instrumentation turned on. Another 35 will follow.
Jupiter is a planet worth studying for many reasons: It's the biggest and most massive in the solar system by a long shot, and was probably the first planet formed. It may even have pushed other early-comers out of the solar system, making way for the planets we know (and live on) today. Jupiter formed out of the materials left behind when our sun was born, and the rest of the solar system shared the leftovers of those leftovers. So poking and prodding at Jupiter could reveal a lot about the origin of our planet, not to mention the fundamentals of solar system formation in general.
But there's one particular thing about Jupiter that gets planetary scientists really excited: its magnificently powerful magnetic field. Jupiter's magnetosphere — the area of space affected by its magnetic field — is the second largest object in the solar system (dwarfed only by the heliosphere, the area subjected to particles from the sun's own emissions).
The power of Jupiter's magnetic field creates gorgeous light shows in the form of aurorae. On Earth, aurorae, such as the Northern Lights, form when particles from the sun interact with our magnetic field and become excited. The excited particles spewed by Jovian moon Io's volcanic activity help to make these displays much more dramatic on Jupiter than they are at home. Some of them cover areas larger than our entire planet.
One of the new infrared images captures Jupiter's southern aurorae for the first time, which will allow scientists to study the phenomenon in greater detail. Meanwhile, images of the north pole reveal just how little we know about the king of the planets.
"First glimpse of Jupiter's north pole, and it looks like nothing we have seen or imagined before," principal investigator Scott Bolton said in a statement. "It's bluer in color up there than other parts of the planet, and there are a lot of storms. There is no sign of the latitudinal bands or zone and belts that we are used to — this image is hardly recognizable as Jupiter. We're seeing signs that the clouds have shadows, possibly indicating that the clouds are at a higher altitude than other features."
The mission's Radio/Plasma Wave Experiment (Waves) adds an audio element to our exploration of Jupiter, picking up the radio waves naturally emitted by the planet's dazzling aurorae:
"Jupiter is talking to us in a way only gas giant worlds can," Bill Kurth, co-investigator for the Waves instrument, said in a statement. "Waves detected the signature emissions of the energetic particles that generate the massive auroras that encircle Jupiter's north pole. These emissions are the strongest in the solar system. Now we are going to try to figure out where the electrons come from that are generating them."