NASA's Juno unveils Jupiter's chilly poles, Io's hot secrets
Scientists from NASA have published the latest research findings from the Juno mission, the probe that is orbiting Jupiter. The analyses focus on the polar cyclones on this giant planet and the volcanic activity of its moon, Io.
During the 53rd orbit around Jupiter on February 15, 2023, the Juno probe began experiments related to radio occultations, aimed at studying the structure of the planet's gaseous atmosphere. This method involves sending a radio signal from Earth to the probe, which then sends it back after passing through Jupiter's atmosphere twice. By analyzing the refraction of the 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. Among other things, these experiments have provided the first temperature measurement of the stratosphere near Jupiter's north pole. It was found to be 11 degrees Celsius cooler than the surrounding regions, and the winds reach speeds of over 100 mph.
Researchers also focused on analyzing polar cyclones in Jupiter's north. 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 due to a phenomenon known in meteorology as "beta drift." This results from the interaction of the Coriolis force with rotating wind systems. On Earth, hurricanes also experience 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 volcanic activity on Io. The JIRAM instrument, alongside the microwave radiometer MWR, has revealed that under Io's cooled crust, there still exists hot magma that 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.
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 recorded history is still spewing lava and ash. It was identified in infrared images on December 27, 2022. The Juno probe plans to fly close to Io on May 6, approaching within 55 thousand miles. Scientists hope for further observations of this ongoing eruption.
