Jupiter's fearsome polar cyclones are driven by similar forces to the huge ocean vortices on Earth, study suggests
- Researchers examined an array of infrared images of Jupiter's polar cyclones
- They then calculated the speed, height and other factors of these large storms
- The team found that the storms are powered in a similar way to ocean cyclones
The fearsome cyclones that stretch across Jupiter's poles are driven by forces that are similar to the huge ocean vortices on Earth, a new study has revealed.
Photographs of rich turbulence in the polar regions of Jupiter's gassy atmosphere were sent back to Earth by NASA's Juno spacecraft to be studied by scientists.
Using these images, a team from the University of California San Diego, compared the motion and physics of Jupiter's turbulence to large cyclones on the Earth.
The team say that understanding energy systems on Jupiter, at a much larger scale than on Earth, could help explain the mechanisms at play on our own planet.
JUPITER: THE BASICS
Jupiter is the fifth planet from the Sun and the largest in our solar system.
It is a massive ball of gas that is made mostly of hydrogen and helium, with some heavy elements.
'Jupiter's familiar stripes and swirls are actually cold, windy clouds of ammonia and water, floating in an atmosphere of hydrogen and helium,' said NASA.
'Jupiter’s iconic Great Red Spot is a giant storm bigger than Earth that has raged for hundreds of years.'
The planet is twice as large as all of the other planet's combined, and the Great Red Spot alone is large enough to fit the entire Earth insidee.
One spacecraft – NASA's Juno orbiter – is currently exploring this giant world.
Facts and figures
Distance from Sun: 750 million km
Orbital period: 12 years
Surface area: 61.42 billion km²
Radius: 69,911 km
Mass: 1.898 × 10^27 kg (317.8 M⊕)
Length of day: 0d 9h 56m
Moons: 53 with formal designations; innumerable additional moonlets
Using an array of images, alongside principles used in geophysical fluid dynamics, lead author Lia Siegelman found evidence to prove a longtime hypothesis, that moist convection — when hotter, less dense air rises — drives cyclones on Jupiter.
'When I saw the richness of the turbulence around the Jovian cyclones with all the filaments and smaller eddies, it reminded me of the turbulence you see in the ocean around eddies,' the researcher explained.
'These are especially evident on high-resolution satellite images of plankton blooms for example.'
Understanding Jupiter's energy system, a scale much larger than Earth's one, could also help us understand the physical mechanisms at play on our own planet by highlighting some energy routes that could also exist on Earth.
'To be able to study a planet that is so far away and find physics that apply there is fascinating,' she said. 'It begs the question, do these processes also hold true for our own blue dot?'
Juno is the first spacecraft to capture images of Jupiter's poles, as previous satellites have orbited the equatorial region of the giant world.
Juno is equipped with two camera systems, one for visible light images and another that captures heat signatures using the Jovian Infrared Auroral Mapper (JIRAM).
The team studied infrared images of the north polar region, particularly around the polar vortex cluster, and from the images they could calculate wind speed and direction. They did this by tracking movement of clouds between images.
They then interpreted infrared images in terms of cloud thickness, finding that hot regions corresponded to thin clouds, giving a view deeper into the atmosphere.
Cold regions represent thick cloud cover, blanketing Jupiter's atmosphere, and combined give clues to the energy of the system generating turbulence.
Since the clouds of Jupiter are formed when hotter, less dense air rises, the researchers found that the rapidly rising air within clouds acts as an energy source that feeds larger scales up to the large circumpolar and polar cyclones.
Scientists have been able to study these polar cyclones since Juno arrived in the Jupiter system in 2016, with some spanning 620 miles.
There are eight of these cyclones occurring at Jupiter's north pole, and five at its south pole, according to the US researchers.
These storms have been present since that first view five years ago, but researchers are unsure how they originated or for how long they have been circulating, but they now know that moist convection is what sustains them.
Researchers first hypothesised this energy transfer after observing lightning in storms on Jupiter.
Juno will continue orbiting Jupiter until 2025, providing researchers and the public alike with novel images of the planet and its extensive lunar system.
Findings have been published in the journal Nature Physics.
How NASA's Juno probe to Jupiter will reveal the secrets of the solar system's biggest planet
The Juno probe reached Jupiter on July 4, 2016, after a five-year, 1.8 billion-mile (2.8bn km) journey from Earth.
Following a successful braking manoeuvre, it entered into a long polar orbit flying to within 3,100 miles (5,000 km) of the planet's swirling cloud tops.
The probe skimmed to within just 2,600 miles (4,200 km) of the planet's clouds once a fortnight - too close to provide global coverage in a single image.
No previous spacecraft has orbited so close to Jupiter, although two others have been sent plunging to their destruction through its atmosphere.
To complete its risky mission Juno survived a circuit-frying radiation storm generated by Jupiter's powerful magnetic field.
The maelstrom of high energy particles travelling at nearly the speed of light is the harshest radiation environment in the Solar System.
To cope with the conditions, the spacecraft was protected with special radiation-hardened wiring and sensor shielding.
Its all-important 'brain' - the spacecraft's flight computer - was housed in an armoured vault made of titanium and weighing almost 400 pounds (172kg).
The craft is expected to study the composition of the planet's atmosphere until 2025.