What did Juno Uncover on Jupiter?


Data suggests that Jupiter's atmospheric winds last longer than similar atmospheric processes found here on Earth and are unlike anything else in our solar system, NASA explains.

The image captures the swirling cloud formations around the south pole of Jupiter, looking up toward the equatorial region.

Unfortunately, 2018 will mark the past year for Juno; researchers plan on performing a controlled deorbit for the spacecraft, sending it into Jupiter's atmosphere to disintegrate. Juno's Jovian Infrared Auroral Mapper (JIRAM) instrument can measure the planet's heat percolating through the atmosphere, probing the weather systems up to 45 miles (72 kilometers) below, day or night.

"Prior to Juno we did not know what the weather was like near Jupiter's poles", says Alberto Adriani, co-investigator of Juno.

Adriani explained that the width of each of the northern cyclones is the distance between New York City and Naples, and the Southern cyclones are even more massive in comparison. The wind speeds exceed Category 5 hurricane strength in places, reaching 350 kmph.

The co-investigator also added that the remarkable feature about the cyclones is that they are enduring and very close together.

We know that Jupiter is about 11 times bigger than Earth, yet its size doesn't slow its rotation; Jupiter has a rotation of 10 hours. Scientists thought they'd find something similar to the six-sided cloud system spinning over Saturn's north pole. Astronomers aren't sure about the science behind these shapes, how they interact and why there's a difference between the atmospheres of Jupiter and Saturn.

Juno's data showed a small but significant asymmetry between the gravitational field of Jupiter's northern and southern hemispheres, driven by the vast jet streams.

"Since Jupiter is basically a giant ball of gas, the initial expectation was that there would be no asymmetries in the gravity field between the north and south", said Professor Yohai Kaspi from The Weizmann Institute in Israel and lead author of the research paper recently submitted to Nature. "It's like going from a 2-D picture to a 3-D version in high definition".

As for Juno, NASA now has plans to continue using the spacecraft to reveal more of Jupiter's secrets through at least July 2018.

The scientists said Jupiter's jet streams, related to the familiar stripes on its surface, plunge some 3,000 km (1,800 miles) below cloud level, and that its deep interior is comprised of a fluid hydrogen and helium mixture that rotates as if it were a solid body. As a comparison, our atmosphere accounts for less than one-millionth of Earth's mass.

In the planet's north pole, one large cyclone is surrounded by eight other polar cyclones, and a large south polar cyclone is encircled by five cyclones, according to the new study produced using data from NASA's Jupiter-exploring Juno probe.