“We knew, going in, that Jupiter would throw us some curves. …There is so much
going on here that we didn’t expect that we have had to take a step back
and begin to rethink of this as a whole new Jupiter.”

– Scott Bolton, Ph.D., Juno Principal Investigator,
Southwest Research Inst., San Antonio, TX

Jupiter, the largest planet in our solar system has some beautiful surprises bundled into it. These surprises came into light when NASA’s Juno spacecraft entered its orbit on July 4, 2016. These findings from the first data-collection pass were published in the journal Science along with 44 more papers in Geophysical Research Letters on May 26, 2017.

Juno has uncovered several findings of this giant planet. The results revealed that Jupiter has Earth-sized swirling dense storms rubbing together at its poles. Also, Jupiter’s poles do not look alike.

1. Aurora lights

NASA Hubble Space Telescope image of Jupiter and blue aurora at the massive gas planet's poles. Credit: 2016 NASA, ESA, J. Nichols, Univ. of Leicester.

Juno revealed that Auroral lights were shining at both the polar regions. Juno’s initial observations stated that charged electrons that were coming out of the planet flowed against the solar radiation that was flowing into the earth’s magnetic fields from the sun that caused the auroral emissions.

Juno’s ultraviolet spectrograph recorded this image of Jupiter’s southern aurora. Credit: NASA/JPL-Caltech/SWRI

But later, the studies stated that these lights were a result of the slamming generated between the atmospheric molecules and the particles that absorb energy.

2. Jupiter’s ammonia band

NASA’s Juno spacecraft carries an instrument called the Microwave Radiometer, which examines Jupiter’s atmosphere beneath the planet’s cloud tops. The data presented at right show abundances of ammonia deep in Jupiter’s atmosphere, with red representing high concentrations and blue representing low concentrations. Credit: NASA/JPL-Caltech/SwRI

Another salient feature that came to light was Jupiter’s ammonia band. The data indicates that Jupiter’s iconic belts and zones are mysterious, with the belt near the equator penetrating all the way down, while the belts and zones at other latitudes seem to evolve to other structures. There is also suggestion that bands of ammonia were arising from around 200 miles down in Jupiter’s equator.

3. A large fuzzy metallic hydrogen core

NASA’s Juno spacecraft is investigating the structure and convection of Jupiter’s interior by reaching through the meteorological layer, the top layer of the planet’s atmosphere. A possible inner “rock” core is shown, surrounded by a metallic hydrogen envelope (shown in blue) and outer envelope of molecular hydrogen (shown in brown), all hidden beneath the visible cloud deck. Juno’s gravity field data will reveal new clues about Jupiter’s core. Credit: NASA/JPL-Caltech/SwRI

Jupiter has a fuzzy core. It is not like a rocky core or a hydrogen core. It is much bigger in size. Scientists believe that the core may have dissolved partially due to some large motions or zonal winds that occur below the planet’s cloud tops.

4. Jupiter’s magnetic field

Jupiter is surrounded by an enormous magnetic field called the magnetosphere, which has a million times the volume of Earth's magnetosphere.

The magnetic field on Jupiter is stronger and complex. Unlike earth’s magnetic field, which is generated by rotating electrically charged liquid iron, Jupiter’s magnetic fields arise from hydrogen. Juno’s Microwave Radiometer (MWR) revealed that Jupiter’s iconic belts and zones had a certain mystery about them. It showed that these zones and belts penetrated all the way down near the equator while those at other latitudes seemed to evolve into some other structures.

 Before even Juno was sent into space, it was known that Jupiter has an intense magnetic field in the entire solar system which was affirmed with Juno’s magnetometer Investigation (MAG). It revealed that the magnetic field on Jupiter exceeded at 7.766 Gauss and was ten times stronger than that we have on earth. On earth, we have solar particles streaming from the sun that interacts with our magnetic fields. On the other hand, Jupiter has charged electrons that are discharged into space.

5. ‘It’s snowing on Jupiter’.

Left: A Nasa image of Jupiter’s south pole. The oval features are cyclones up to 600 miles wide /Right:Small bright clouds dot Jupiter’s entire south tropical zone in this image acquired by JunoCam on NASA’s Juno spacecraft on May 19, 2017

Spectacular new images captured by NASA’s Jupiter-orbiting Juno spacecraft show fluffy-looking white clouds casting their comparably tiny shadows on the giant planet’s monstrous, multicolored cloud decks.

The white clouds, which get up to 50 miles (80 kilometers) wide or so, are high up in Jupiter’s atmosphere — so high that they’re very cold, and the material they shed is therefore almost certainly frozen, Juno team members said.

“It’s snowing on Jupiter, and we’re seeing how it works,” said Juno principal investigator Scott Bolton, of the Southwest Research Institute in San Antonio.

Jack Connerney, Juno deputy principal investigator and the lead for the mission’s magnetic field investigation at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, states, “The magnetic field on Jupiter looked lumpy. It is stronger in some places and weaker in others”. Jack said that this uneven distribution could have been generated by the dynamo action that takes places near the surface which is above the layer of metallic hydrogen.

Juno’s next close-up encounter with Jupiter is set for July 11, when the orbiter will pass above the Great Red Spot for the first time.

According to Scott Bolton the discoveries made by Juno so far are “making us rethink how giant planets work, not just in our own solar system, but giant planets are really important throughout the galaxy and the universe”.

Image Credit:NASA via BBC (Image Source)

• Jupiter is 11 times wider than Earth and 300 times more massive
• It takes 12 Earth years to orbit the Sun; a ‘day’ is 10 hours long
• In composition it resembles a star; it’s mostly hydrogen and helium
• Under pressure, the hydrogen assumes a state similar to a metal
• This ‘metallic hydrogen’ could be the source of the magnetic field
• Most of the visible cloud tops contain ammonia and hydrogen sulphide
• Jupiter’s low-latitude ‘bands’ play host to very strong east-west winds
• The Great Red Spot is a giant storm vortex twice as wide as Earth

source:earthfiles