Juno probes Jupiter's stormy north pole
NASA has provided the first close-up and personal view of Jupiter's north pole with the release of images from the Juno orbiter's close encounter with the gas giant. According to the space agency, the unmanned spacecraft returned six megabytes of data over a one-and-a-half day period from its six-hour transit on August 27 at an altitude of 2,500 mi (4,200 km) above Jupiter's clouds. The result is more than a few surprises.
One obvious novelty is that Jupiter's north pole is bluer than expected and the Jovian arctic is a stormy region devoid of the familiar latitudinal bands found closer to the equator. Many of the clouds show shadows, which indicate that they may be at a higher altitude than surrounding features. In addition, there is a hexagonal feature at the north pole – something that has been observed on Saturn, but this is a first for Jupiter.
Along with the JunoCam, which sent back spectacular images with more to come in future flybys, the probe's suite of eight scientific instruments were also brought into play. The Italian Space Agency's Jovian Infrared Auroral Mapper (JIRAM) looked into the infrared regions and showed remarkable hot spots at both the north and south poles, while also providing the first look at the planet's southern aurora. Alberto Adriani, JIRAM co-investigator from Istituto di Astrofisica e Planetologia Spaziali, Rome, says that the aurora is very bright and well structured, and that the high level of detail in the images will reveal more about the aurora's morphology and dynamics.
Meanwhile, the Radio/Plasma Wave Experiment (Waves) sent back the closest observation ever of the howling storm of radio emissions first observed by Bernard Burke and Kenneth Franklin of the Carnegie Institution in 1955.
"Jupiter is talking to us in a way only gas-giant worlds can," says Bill Kurth, co-investigator for the Waves instrument from the University of Iowa, Iowa City. "Waves detected the signature emissions of the energetic particles that generate the massive auroras which 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."
The Juno mission began in August 2011 and arrived at Jupiter on July 4, 2016 after a roundabout journey that included a flyby of Earth in 2013. Intended to return the highest-resolution images of Jupiter in history with a special emphasis on the north and south polar regions, it will also study Jupiter's early history, determine the deep structure of the planet, and study its magnetic fields.
Infrared image of the southern aurora of Jupiter, as captured by NASA's Juno spacecraft on August 27, 2016
It made its first close orbital flyby of Jupiter on August 27 at 6:44 am PDT (13:44 GMT) while traveling at a speed of 130,000 mph (208,000 km/h), coming to within 2,600 mi (4,200 km) of Jupiter's cloud tops in the first and closest of 36 flybys it will make during its mission. It will make 35 more flybys over the next 20 months before making a controlled dive into the Jovian atmosphere, where it will burn up to avoid biological contamination of Jupiter's moons.
The first NASA video below shows Jupiter in infrared, while the second provides a look and listen to the planet's auroras.Source: