NASA’s Juno spacecraft ‘hears’ Jupiter’s moon Ganymede

Juno principal investigator Scott Bolton of the Southwest Research Institute in San Antonio fires a 50-second soundtrack created from data collected during the mission’s close-in flight to the Jovian Ganymede moon on June 7, 2021. Juno Waves ToolTuned with electrical and magnetic radio waves produced in Jupiter’s magnetosphere, they collected data about those emissions. Its frequency was then converted into the vocal range to make the audio track.

“This soundtrack is wild enough to make you feel as if you’re riding along as Juno sails past Ganymede for the first time in more than two decades,” Bolton said. “If you listen closely, you can hear the sudden change of higher frequencies around the middle of the recording, which represents the entry into a different region in Ganymede’s magnetosphere.”

https://www.youtube.com/watch?v=iHQJ6B7DP0U
Radio emissions collected during Juno on June 7, 2021, as it flies over Jupiter’s moon Ganymede, are shown both visually and acoustically. credit: NASAJet Propulsion Laboratory-Caltech/SwRI/Iowa State University
Detailed analysis and modeling of the wave data is underway. William Kurth said from the site University of Iowa in Iowa City, co-principal investigator on the Waves investigation.

At the time of Juno’s closest approach to Ganymede—during the mission’s 34th flight around Jupiter—the spacecraft was 645 miles (1,038 km) from the lunar surface and traveling at a relative speed of 41,600 mph (67,000 km/h).

Magnetic Jupiter

Jack Conerney of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, is the principal investigator for the Juno magnetometer and is the mission’s deputy principal investigator. His team produced the most detailed map ever obtained of Jupiter’s magnetic field.

Compiled from data collected from 32 orbits during the main Juno mission, the map provides new insights into the gas giant’s mysterious Great Blue Spot, a magnetic anomaly at the planet’s equator. Juno data indicate a change in the gas giant’s magnetic field during the spacecraft’s five years in orbit, and that the Great Blue Spot is drifting eastward at about 2 inches (4 cm) per second relative to the rest of Jupiter. Inland, the planet wrapped in about 350 years.

By contrast, the Great Red Spot – the long-duration atmospheric cyclone located south of Jupiter’s equator – is drifting west in a relatively fast segment, orbiting the planet in about four and a half years.

In addition, the new map shows that Jupiter’s zonal winds (the jet streams that run from east to west and west to east, giving Jupiter its distinctive appearance) are breaking up the Great Blue Spot. This means that the winds of the measured region on the surface of the planet reach deep into the planet’s interior.

The new magnetic field map allows Juno scientists to make comparisons with Earth’s magnetic field. The team’s data indicates that the motion of the dynamo – the mechanism by which a celestial body generates a magnetic field – within Jupiter’s interior occurs in metallic hydrogen, below a layer expressing “helium rain”.

Data that Juno collects during extended mission It may also reveal the mysteries of the dynamo’s impact not only on Jupiter but also on other planets, including Earth.

Earth’s oceans, Jupiter’s atmosphere

Lia Siegelman, a physical oceanographer and postdoctoral fellow at the Scripps Institution of Oceanography at the University of California, San Diego, decided to study Jupiter’s atmospheric dynamics after noticing that cyclones at Jupiter’s pole seemed to share similarities with the ocean eddies through which she studied. time as a PhD student.

“When I saw the richness of the turbulence surrounding Hurricane Jovian, with all the threads and the smaller eddies, it reminded me of the turbulence you see in the ocean around the eddies,” Siegelman said. This is particularly evident in high-resolution satellite images of eddies in Earth’s oceans revealed by plankton blooms that act as a flow-tracker.

The simplified model of Jupiter’s pole shows that the geometric patterns of eddies, such as those observed on Jupiter, appear spontaneously and remain forever. This means that the planet’s basic geometric configuration allows these intriguing structures to form.

Although Jupiter’s energy system is much larger than Earth’s, understanding the dynamics of Jupiter’s atmosphere can help us understand the physical mechanisms that play a role on our planet.

Arming Perseus

Juno’s team has also released its latest image of Jupiter’s faint dust ring, taken from inside the ring viewed by the spacecraft’s Stellar Reference Unit navigation camera. The brightest thin bands and the sight of adjacent dark areas in the image are associated with dust from Jupiter’s two small moons, Metis and Adrastea. The image also captures the arm of the constellation Perseus.

“It’s astonishing to be able to stare at these familiar constellations from a spacecraft half a billion miles away,” said Heidi Becker, principal investigator for the Juno Stellar Reference Module at NASA’s Jet Propulsion Laboratory in Pasadena. “But it pretty much all looks the same when we appreciate them from our own backyards here on Earth. It’s a stunning reminder of how small we are and how much we have left to explore.”

This artist’s view shows Juno above Jupiter’s north pole, with the aurora borealis glowing. Jupiter’s magnetic field surrounds the planet. A radio wave from the aurora appears passing through the spacecraft, where it is intercepted by a wave probe, whose sensors are highlighted in light green. credit: NASA

Juno Waves

Waves measures radio and plasma waves in Jupiter’s magnetosphere, which helps us understand the interactions between the planet’s magnetic field and the atmosphere and magnetosphere. The waves also pay special attention to the activity associated with the aurora borealis.

Jupiter’s magnetosphere, a massive bubble created by the planet’s magnetic field, traps plasma, an electrically charged gas. Activity within this plasma, which fills the magnetosphere, emits waves that only an instrument like the waves can detect.

Because the plasma conducts electricity, it behaves like a giant circuit, connecting one region to another. The activity can thus be felt on one end of the magnetosphere elsewhere, allowing Juno to observe the processes taking place in this entire gigantic region of space around Jupiter. Radio waves and plasmas move through space around all the giant exoplanets, and previous missions have been equipped with similar instruments.

Juno Waves consists of two sensors; One detects the electrical component of radio waves and plasmas, while the other is sensitive to the magnetic component of plasma waves. The first sensor, called an electric dipole antenna, was a V-shaped antenna, four meters from tip to tip — similar to the rabbit ear antennas that were common in televisions. A magnetic antenna – called a magnetic search coil – consists of a coil of fine wire wrapped 10,000 times around a 6-inch (15-cm) core. The search coil measures magnetic fluctuations in the audio frequency range.

More about the mission

The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, California, directs the Juno mission for principal investigator Scott J. Bolton, of the Southwest Research Institute in San Antonio. Juno is part of NASA’s New Frontiers Program, which is managed at NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington. Lockheed Martin Space in Denver built and operated the spacecraft.