A conceptual image featuring Jupiter and Io and their interaction. Jupiter's magnetic field lines are represented in yellow/orange/red lines. The blue cloud represents the Io plasma torus which is a region withing Io's orbit with a higher concentration of ions and electrons. The grey cone represents the emmergence of radio emissions. The long white line represents Juno's orbit. Credit: NASA/GSFC/Jay Friedlander

NASA Spacecraft Detects Radio Emissions From Jupiter’s Moon Io—10 Things You Should Know

Juno’s onboard science instrument Waves “listened” to radio emissions coming from the side of Jupiter’s magnetic field and gave scientists the opportunity to determine the boundaries of the regions with radiation.

By “listening” to the signal from the stream of electrons flowing down to Jupiter from its volcanically active satellite Io researchers found probable zones of this powerful radio emission inside the giant planet’s magnetic field. These new findings provide a deeper understanding of the vast magnetic fields generated by gas giants such as Jupiter.

Everything you need to know about the strange radio emissions

1. Jupiter has the most extensive and powerful magnetic field of all planets in the solar system – it is about 20,000 times stronger than the magnetic field of our planet.

2. This magnetic field is continuously bombarded by the solar wind – a stream of electrically charged particles and magnetic fields blowing from the direction of the sun.

3. In the magnetic field of Jupiter are its satellites, and the closest to the giant planet is the moon of Io – which is constantly influenced by gravity from Jupiter and its two more distant large satellites.

4. As a result, the material of the satellite of Io is constantly crumpled, which leads to the generation of a huge amount of thermal energy.

5. The release of this thermal energy is carried out in the form of intense volcanic activity on the satellite (see the image below).

6. Part of the material ejected as a result of volcanic activity is split into electrically charged electrons and ions and is captured by the giant planet’s magnetic field.

7. Electrons accelerated in a magnetic field emit radio waves in the decameter range, recorded using the Juno Waves instrument.

An old image of Io, captured in 2007 by the Long Range Reconnaissance Imager. To date, this is the best view of the eruption from the Tvashtar volcano (visible on the top left). Two more smaller volcanic plumes are visible on the left and front-bottom of the moon. Credit: NASA/JHUAPL/SwRI
An old image of Io, captured in 2007 by the Long Range Reconnaissance Imager. To date, this is the best view of the eruption from the Tvashtar volcano (visible on the top left). Two smaller volcanic plumes are visible on the left and front-bottom of the moon. Credit: NASA/JHUAPL/SwRI

8. The findings allowed the team of astronomers to find out that the energies of the electrons that are the sources of these radio emissions are actually about 23 times higher than expected.

9. In addition, these electrons do not have to be from the satellite of Io, but can, for example, be part of the streams of the solar wind, the authors noted.

10. Their brand new study is published in the Journal of Geophysical Research: Planets.

More research on Jupiter and its moons

Before scientists revealed the truth about radio emissions on Jupiter, a different team of planetologists found that the physical processes that govern proton auroras on Earth are responsible for the appearance of X-ray auroras on Jupiter. Scientists came to this conclusion after analyzing data from the XMM-Newton space telescope and the Juno interplanetary station, which in the summer of 2017 simultaneously tracked Jupiter.

It is expected that “Juno” will continue to study Jupiter’s auroras, and in the future, it will be replaced by the automatic station JUICE (Jupiter Icy moons Explorer).

At the same time, there is one more mission towards the Jupiter system that is currently in development. Europa Clipper will explore Europa, a large icy moon of Jupiter with a global subsurface ocean that is kept liquid by tidal forces from the gas giant. Due to cracks in the crust, geysers have been repeatedly observed on the satellite, and hydrothermal processes can take place at its bottom, which can create favorable conditions for the development of microbiological life.

The device will map the surface of Europa, determines the composition and thickness of the ice crust, as well as the composition and properties of the ocean.

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Brabaw, K. (2021, July 23). Jupiter’s volcanic moon Io is emitting strange radio waves and NASA’s Juno probe is listening. Space.com.
O’Neill, M. (2021, July 22). Cause of Jupiter’s X-Ray Aurora Revealed – Mystery Has Puzzled Scientists for 40 Years. SciTechDaily.
Steigerwald, B. (2021, May 20). Juno Tunes into Jovian Radio Triggered by Jupiter’s Volcanic Moon. NASA.

Written by Vladislav Tchakarov

Hello, my name is Vladislav and I am glad to have you here on Curiosmos. My experience as a freelance writer began in 2018 but I have been part of the Curiosmos family since mid-2020. As a history student, I have a strong passion for history and science, and the opportunity to research and write in this field on a daily basis is a dream come true.

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