A Strange Signal Detected From Jupiter's Moon

Jupiter's four largest moons, discovered 400 years ago by Galileo Galilei, are IO, Europa, Ganymede Ganymede and Callisto.

Their worlds are fascinating, and some of them hide oceans that could harbor life.

Scientists say the Juno probe has detected FM radio signals from one of the giant moons.

Where did the signal come from? What other secrets are Jupiter's other moons hiding?

The Juno spacecraft is still roaming through space, and for the first time since its launch, it has received FM radio signals from Jupiter's moon Ganymede, which can also be found on Earth.

In fact, we use this signal every day, just like our Wi-Fi.

Ganymede is the largest moon in the entire solar system, and if it orbits the Sn, it would itself be a planet larger than Mercury.

Ganymede has no atmosphere and is the only moon known to have a powerful magnetosphere, which sometimes produces auroras influenced by a salty ocean beneath the moon.

These wobbly aurora sightings gave researchers evidence that Ganymede's underground ocean may be liquid and much saltier than earth's oceans.

The FM signals from Ganymede come from electrons in an electromagnetic field, a process that causes the electrons to spin and oscillate at speeds far below their spin speed.

The Juno probe detected a five-second radio burst in late 2020 as Ganymede passed through Jupiter's polar region, where the gas giant's magnetic field interacts with it.

Could there be life on Ganymede?

We're sure the signal isn't from alien life. It's cold on Ganymede, around -121 degrees Celsius, but during a flyby, the Galileo probe detected a dense stream of hydrogen atoms escaping from the moon's thin atmosphere.

That means there's a lot of oxygen, locked up or suspended on its icy surface, hydrogen atoms are the lightest atoms, and Ganymede has a weak gravitational field, so hydrogen escapes and atomic oxygen stays on the surface.

Some researchers think there could be as much oxygen on Ganymede's icy surface as there is on Earth if conditions were right for life in ganymede's underground ocean.

Some scientists think the pressure at the bottom of any ocean would be so high that it could turn into ice, but more discoveries are needed, though this moon is not the best candidate for life.