Juno mission unveils cyclones on Jupiter and Io's fiery heart
Scientists from NASA have published the latest research findings from the Juno mission, the probe orbiting Jupiter. The analyses focus on the polar cyclones on this giant planet and volcanic activity of its moon - Io.
During the 53rd orbit around Jupiter, on 15 February 2023, the Juno probe began experiments related to radio occultations, aimed at studying the structure of the planet's gaseous atmosphere. The method involves sending a radio signal from Earth to the probe, which then sends it back, with the signal passing through Jupiter's atmosphere twice. By analysing the refraction of radio waves caused by the atmospheric layers, scientists can draw conclusions regarding temperature and gas density.
We know more about Jupiter
So far, 26 such experiments have been conducted, through which, among other things, the first temperature measurement of the stratosphere near the north pole of Jupiter was obtained. It was found to be 11 degrees Celsius cooler than the surrounding regions, and the winds reach speeds of over 160 km/h.
Researchers also focused on analysing polar cyclones in the north of Jupiter. Using data from the JunoCam (visible light images) and JIRAM (infrared imaging spectrometer) instruments, they tracked the movement of a large polar cyclone and eight surrounding cyclones.
It was discovered that each of these cyclones gradually shifts towards the pole, which is the result of a phenomenon known in meteorology as "beta drift". This results from the interaction of the Coriolis force with rotating wind systems. On Earth, hurricanes are also subject to this phenomenon, but they dissipate before reaching the polar zones. On Jupiter, cyclones form clusters in polar regions, and their movement slows as they begin to interact with each other.
Moon Io: new discoveries
Another significant finding is new data regarding volcanism on Io. The JIRAM instrument, in conjunction with the microwave radiometer MWR, has allowed the observation that under Io's cooled crust there still exists hot magma, which hasn't yet solidified. Cooling lava streams have been identified in many places, and about 10 percent of the moon's surface contains slowly cooling lava just beneath the surface.
Shannon Brown from the Juno mission, working at NASA's Jet Propulsion Laboratory in Southern California, compared the volcanoes, lava fields, and subsurface lava streams on Io to a car radiator, as they efficiently transport heat from the interior to the surface, cooling in the vacuum of space.
The most energetic eruption on Io in history is still spewing lava and ash. It was identified in infrared images on 27 December 2022. The Juno probe plans to fly close to Io on 6 May, approaching to within 88,000 km. Scientists are hoping for further observations of this ongoing eruption.
