Juno Tunes Into Jupiter’s Radio Transmissions

NASA’s Juno spacecraft has observed the interaction of particles from Io’s volcanoes with Jupiter’s massive magnetic field, causing radio transmissions.

IMAGE: This is a representation of the Jupiter-Io system and interaction. The blue cloud is the Io plasma torus, which is a region of higher concentration of ions and electrons located at Io’s orbit. This conceptual image shows the radio emission pattern from Jupiter. The multi-colored lines represent the magnetic field lines that link Io’s orbit with Jupiter’s atmosphere. The radio waves emerge from the source which is located at the line of force in the magnetic field and propagate along the walls of a hollow cone (grey area). Juno receives the signal only when Jupiter’s rotation sweeps that cone over the spacecraft, in the same way a lighthouse beacon shines briefly upon a ship at sea. Juno’s orbit is represented by the white line crossing the cone. CREDIT: NASA/GSFC/Jay Friedlander

By now, most of my audience likely knows that my favorite moon is Io, the closest in of Jupiter’s four Galilean moons. Io is an incredibly volcanic body, constantly being squeezed by the gravitational forces of both Jupiter and two of the other Galilean moons. The squeezing heats up Io’s interior, which then provides the power to generate multiple volcanic eruptions all over the small moon. Images of lava fountains have been captured by the Galileo, Voyager, and New Horizons spacecraft. Now, NASA’s Juno is at Jupiter, collecting data on the gas giant and its moons, Io included.

Jupiter, of course, is the largest planet in our solar system; it is the planet against which we compare exoplanets. We look at it as a standard, despite it being wildly different from every other planet in our solar system. One of the ways that Jupiter is different is its huge magnetic field. That’s the main reason Juno was sent to Jupiter: to gain an understanding of that magnetic field, which stretches from 3.2 million kilometers in the direction of the Sun to more than 965 million kilometers away from the Sun. It’s huge. So big as to be incomprehensible to the human mind. And yet, we can use what we learn about…