Jupiter's Wild North Pole, Southern Auroras Photographed for 1st Time — **NASA’s Juno spacecraft captured this image of Jupiter’s north pole on Aug. 27, from a distance of 120,000 miles (195,000 kilometers).**
**Credit: NASA/JPL-Caltech/SwRI/MSSS**

NASA's Juno spacecraft has beamed home the first-ever photos of Jupiter's north pole, and scientists can hardly believe their eyes.

Juno captured the images on Aug. 27, when the probe skimmed just 2,600 miles (4,200 kilometers) above Jupiter's cloud tops during the first of three dozen close flybys of the solar system's largest planet.

"First glimpse of Jupiter's north pole, and it looks like nothing we have seen or imagined before," Juno principal investigator Scott Bolton, of the Southwest Research Institute in San Antonio, said in a statement. [Photos: NASA's Juno Mission to Jupiter]

This view of Jupiter's north pole — captured by NASA's Juno probe on Aug. 27, 2016, from a distance of 48,000 miles (78,000 kilometers) — shows storms and weather systems unlike any seen elsewhere in the solar system.
**Credit: NASA/JPL-Caltech/SwRI/MSSS**

"It's bluer in color up there than other parts of the planet, and there are a lot of storms," Bolton added. "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."

Saturn has a huge hexagonal storm swirling at its north pole. But Jupiter lacks such a vortex, the new photos show.

"There is nothing on Jupiter that anywhere near resembles that," Bolton said. "The largest planet in our solar system is truly unique. We have 36 more flybys to study just how unique it really is."

The $1.1 billion Juno mission launched in August 2011 and reached Jupiternearly five years later, on July 4 of this year. But Juno's instruments were turned off on this latter date, because mission team members wanted to focus on executing the make-or-break, 35-minute orbit-insertion burn.

**NASA’s Juno probe took this image of Jupiter’s south pole on Aug. 27, 2016, from a distance of 58,700 miles (94,500 kilometers).**
**Credit: NASA/JPL-Caltech/SwRI/MSSS**

So the Aug. 27 approach marked the first opportunity for the Juno team to photograph Jupiter up close and make detailed measurements with its suite of eight science instruments. (The spacecraft is currently in a highly elliptical, 54-day orbit around the planet.)

One of these instruments, the Jovian Infrared Auroral Mapper (JIRAM), captured views of Jupiter's north and south poles in infrared light, revealing hot spots that had never been seen before, mission scientists said.

**Juno captured this infrared image of Jupiter’s southern lights on Aug. 27, 2016. Such views are not possible from Earth.**
**Credit: NASA/JPL-Caltech/SwRI/ASI/INAF/JIRAM**

Like Earth, Jupiter has auroras — dramatic light displays that dance above the planet's north and south polar regions. JIRAM got unprecedented looks at the powerful Jovian southern aurora, Juno team members said.

"We were amazed to see it for the first time," JIRAM co-investigator Alberto Adriani, of the Istituto di Astrofisica e Planetologia Spaziali (Institute of Astrophysics and Space Planetology) in Rome, said in the same statement.

"No other instruments, both from Earth or space, have been able to see the southern aurora," he added. "Now, with JIRAM, we see that it appears to be very bright and well-structured. The high level of detail in the images will tell us more about the aurora's morphology and dynamics."

Juno also managed to "hear" Jupiter's auroras, using the spacecraft's Radio/Plasma Wave Experiment (also known as Waves).

Spectacular aurora lights up Jupiter’s North Pole

Jupiter's Wild North Pole, Southern Auroras Photographed for 1st Time

"Waves detected the signature emissions of the energetic particles that generate the massive auroras which encircle Jupiter's north pole," said Waves co-investigator Bill Kurth, a research scientist in the Department of Physics and Astronomy at the University of Iowa. "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."

Next month, Juno is scheduled to perform another engine burn that will shift the probe into a 14-day-long orbit. The spacecraft will continue gathering data — especially during its close flybys over the planet's poles — before ending its mission with an intentional death dive into Jupiter's atmosphere in February 2018.

**These 10 images show Jupiter growing and shrinking in apparent size before and after NASA's Juno spacecraft made its close approach to the planet on August 27, 2016.**
**Credit: NASA/JPL-Caltech/SwRI/MSSS**

Juno's observations should help scientists better understand Jupiter's composition and structure, including whether the giant planet harbors a core of heavy elements. This information should, in turn, shed light on the formation of Jupiter, the solar system and planetary systems in general, NASA officials have said.

Follow Mike Wall on Twitter @michaeldwall and Google+. Follow us@Spacedotcom, Facebook or Google+. Originally published on Space.com.

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Van Allen Radiation Belts: Facts & Findings — Two giant swaths of radiation, known as the Van Allen Belts, surrounding Earth were discovered in 1958. In 2012, observations from the Van Allen Probes showed that a third belt can sometimes appear. The radiation is shown here in yellow, with green representing the spaces between the belts.
**Credit: NASA/Van Allen Probes/Goddard Space Flight Center**

Earth is surrounded by giant donut-shaped swaths of magnetically trapped, highly energetic charged particles. These radiation belts were discovered in 1958 by the United States' first satellite, Explorer 1. The discovery was led by James Van Allen at the University of Iowa, which eventually caused the belts to be named after him.

Van Allen's experiment on Explorer 1, which launched Jan. 31, 1958, had a simple cosmic ray experiment consisting of a Geiger counter (a device that detects radiation) and a tape recorder. Follow-up experiments on three other missions in 1958 — Explorer 3, Explorer 4 and Pioneer 3 — established that there were two belts of radiation circling the Earth.

This simple picture of the radiation belts persisted for decades until 2012, when a pair of probes was launched to study them in detail. This was the first time that two spacecraft simultaneously studied the radiation belts, trading information with each other to build a bigger picture.

Early probe findings

Part of the interest in the Van Allen belts comes from where they are located. It is known that the belts can swell when the sun becomes more active. Before the probes launched, scientists thought the inner belt was relatively stable, but when it did expand its influence extended over the orbit of the International Space Station and several satellites. The outer belt fluctuated more often.

The Van Allen Probes (formerly known as the Radiation Belt Storm probes)have several scientific goals, including discovering how the particles — ions and electrons — in the belts are accelerated and transported, how electrons are lost and how the belts change during geomagnetic storms. The mission was planned to last two years, but as of August 2016 the probes were still operating at double the expected mission lifetime.

Usually scientists take a few months to calibrate their instruments, but a team with the Relativistic Electron Proton Telescope asked that their instrument be turned on almost immediately (three days after launch). Their reasoning was they wanted to compare observations before another mission, SAMPEX (Solar, Anomalous, and Magnetospheric Particle Explorer), de-orbited and entered Earth's atmosphere.

"It was a lucky decision," NASA said in February 2013, noting that a solar storm had already caused the radiation belts to swell as soon as the instrument was turned on. "Then something happened no one had ever seen before: the particles settled into a new configuration, showing an extra, third belt extending out into space," the agency added. "Within mere days of launch, the Van Allen Probes showed scientists something that would require rewriting textbooks."

**An artist's depiction of the two Van Allen probes orbiting Earth.**
**Credit: JHU/APL**

Protective shield

Data gathered by the probes also showed that the radiation belts shield Earthfrom high-energy particles. "The barrier for the ultrafast electrons is a remarkable feature of the belts," study lead author Dan Baker, of the University of Colorado in Boulder, said in a statement.

"We're able to study it for the first time, because we never had such accurate measurements of these high-energy electrons before." [Gallery: NASA's Van Allen Probes]

Complex configuration

This new information helped scientists model the belts' changes. But there was more information to come. In January 2016, scientists revealed that the shape of the belts depends on what type of electron is being studied. This means the two belts are much more complex; depending on what is being observed, they can be a single belt, two separate belts or just an outer belt (with no inner belt at all.)

"The researchers found that the inner belt — the smaller belt in the classic picture of the belts — is much larger than the outer belt when observing electrons with low energies, while the outer belt is larger when observing electrons at higher energies," NASA wrote at the time. "At the very highest energies, the inner belt structure is missing completely. So, depending on what one focuses on, the radiation belts can appear to have very different structures simultaneously."

What is still poorly understood, however, is what happens when particles from the sun hit the belts during a geomagnetic storm. It is known that the number of electrons in the belts changes, either decreasing or increasing depending on the situation. Also, the belts eventually return to their normal shape after the storm passes. NASA said it isn't clear what kind of storm will cause a specific type of belt configuration. Also, the agency noted, any previous observations were done only with electrons at a few energy levels. More work needs to be done.

Luckily, scientists got the chance to observe a storm up close in March 2015, when one of the Van Allen probes happened to be situated inside the "right" spot in Earth's magnetic field to see an interplanetary shock. NASA describes such shocks as similar to when a tsunami is triggered by an earthquake; in this case, a coronal mass ejection of charged particles from the sun creates a shock in specific areas of the belts.

"The spacecraft measured a sudden pulse of electrons energized to extreme speeds — nearly as fast as the speed of light — as the shock slammed the outer radiation belt," NASA wrote at the time. "This population of electrons was short-lived, and their energy dissipated within minutes. But five days later, long after other processes from the storm had died down, the Van Allen probes detected an increased number of even higher energy electrons. Such an increase so much later is a testament to the unique energization processes following the storm."

The shape of the Van Allen belts can vary widely depending on how energetic the individual electrons are, and general conditions in the Earth’s magnetic environment. During geomagnetic storms (4), all three regions in the belts can balloon.
**Credit: NASA GODDARD/DUBERSTEIN**

Designing better spacecraft

The Van Allen Probes are specially radiation-hardened to withstand the intense environment of the belts. Some spacecraft, however, are more vulnerable — especially when a solar storm hits. At worst, spacecraft can short out due to an electrical overload. Communications can also be disrupted. Fortunately, sometimes instruments can be turned on or off on a spacecraft during a solar storm.

Radiation, of course, also poses a human risk. Astronauts are subject to lifetime radiation limits from their time in space, to reduce any risk of cancer. Since only a few dozen people have spent six months or longer in space, however, it will take decades to understand the long-term effects of radiation on humans.

The astronauts on the ISS do not regularly spend time inside the belts, but from time to time solar storms expand the belts to the orbit of the space station. In the 1960s, several Apollo crews went through the Van Allen belts on their way to and from the moon. Their time in that radiation-intensive region, however, was very short, in part because the trajectory was designed to pass through the thinnest known parts. With more study, astronauts can be better protected for long-term stays in Earth orbit.

"We study radiation belts because they pose a hazard to spacecraft and astronauts," said David Sibeck, the Van Allen Probes mission scientist at NASA's Goddard Space Flight Center in Maryland, in an August 2016 NASA statement. "If you knew how bad the radiation could get, you would build a better spacecraft to accommodate that."

Additional resource

NASA: Van Allen Probes Mission Overview