Jupiter is famous for its bands of clouds that we can see covering the planet, first spotted by Galileo 400 years ago. But scientists were not sure how far down these bands extended. Based on these latest results, it appears the bands cease at 3,000 kilometers in depth, giving rise to this more uniform shape. At its core, the pressure is about 100,000 times the pressure we see on Earth.
“Galileo saw those stripes in Jupiter’s atmosphere many centuries ago, so it is definitely something that we've wanted to know for so long that we are all excited with the results,” added Miguel.
Another major finding from the research is that Jupiter’s gravitational field is not symmetrical from North to South. This was something that was unexpected for such a fluid planet that rotates quickly. It appears that this is caused by the varied wind and atmospheric flows on the planet.
“As the surface jets propagate deep into the planet, they produce a perturbation of the gravity field that we determined with Juno,” Daniele Durante from the Sapienza University of Rome in Italy, one of the study authors, told IFLScience. “That enabled us to infer the depth of Jupiter’s zonal jets, which has remained unknown until today.”
The researchers also found that Jupiter’s atmosphere contains about 1 percent of the planet’s mass, equivalent to about three Earths, which is a huge amount. Earth’s atmosphere, for comparison, makes up just one-millionth of our planet’s total mass.
“The result is a surprise because this indicates that the atmosphere of Jupiter is massive and extends much deeper than we previously expected,” Yohai Kaspi from the Weizmann Institute of Science, Rehovot, Israel, an author on one of the papers, told IFLScience.
These results were made possible thanks to Juno’s unique suite of instruments and its close passes to the planet, just a few thousand kilometers at times, closer than any spacecraft before. Using the radio link between Juno and Earth, scientists were able to measure Juno’s speed near Jupiter to exquisite detail, down to just 0.01 millimeters (0.0004 inches) per second in accuracy.
“This is one-hundredth of the speed of a snail!” Luciano Iess, also from Sapienza University and another author on one of the papers, told IFLScience.
“To measure the gravity of Jupiter one needs to track how a test mass (the Juno spacecraft in our case) falls in the gravity field of the planet with respect to another point in space, such as the Earth.”
But wait, that’s not all.