This NASA picture from March 2017 is an enhanced color image taken by the Juno spacecraft as it performed a close flyby of Jupiter. AFP file photo
MIAMI: An unmanned NASA spaceship circling Jupiter has spotted massive cyclones at the gas giant’s poles, revealing new details about our solar system’s largest planet, researchers said Thursday.
“Images of Jupiter’s previously-unseen poles show a chaotic scene of bright oval features,” said the study in the journal Science.
These ovals, it turns out, are huge swirling storms, some of which measure up to 870 miles (1,400 kilometers) across.
A trove of data from the probe’s initial encounters has shown unexpected features related to these huge brewing storms.
Researchers found “signs of ammonia welling up from the deep atmosphere and forming giant weather systems,” said one of two studies on Jupiter published in the journal Science.
The Juno spacecraft launched in 2011, and made its first tour around Jupiter on August 27, 2016.
Juno moves in an elliptical orbit, skimming within 3,100 miles (5,000 kilometers) of Jupiter’s cloud tops and passing over the poles.
Juno’s main mission began in July and is scheduled to end in February 2018, when the probe will self-destruct by diving into the planet’s atmosphere.
The $1.1 billion project aims to peer beneath the clouds around Jupiter for the first time to learn more about the planet’s atmosphere.
Scientists also want to know how much water the planet contains, because it can tell them a lot about when and how the planet formed.
– Expanding magnetic field –
Juno has also taken measurements of Jupiter’s gravitational field, to see if it has a solid core, as models have predicted.
“Close to the planet, the field greatly exceeded expectations,” said the report.
“It is substantially stronger than models predicted, at 7.766 Gauss, or roughly ten times Earth’s magnetic field.”
A second study in Science looked at the region where the planet’s magnetic field dominates over the solar wind.
It said Jupiter’s magnetic field, or magnetosphere, may have been expanding when Juno approached.
“Juno encountered the giant planet’s bow shock, essentially a stationary shockwave, as it entered the magnetosphere” on June 24, 2016, it said.
“Since the spacecraft only encountered one bow shock as it approached the planet, compared to multiple encounters on subsequent orbits, this suggests that the magnetosphere was expanding in size at the time.”
Juno also detected huge auroras — known on Earth as Northern Lights — and “downward-traveling electron beams that shower energy into Jupiter’s upper atmosphere.”
“Intriguingly these electron showers appear to have a different distribution from those that occur on Earth, suggesting a radically different conceptual model of Jupiter’s interaction with its space environment.” – AFP