Chennai: In a development that caused excitement to those looking for extraterrestrial life, NASA recently detected FM signals from Jupiter’s moon Ganymede for the first time.
Even as the possibility and rumours of alien life surfaced, the space agency was quick to clarify.
“Electrons spiralling in Jupiter’s magnetic field are thought to be the cause of the radio noise we hear,” NASA said in a statement.
The signals from Ganymede originated from electrons due to electromagnetic fields. The process causes electrons within to whirl and oscillate much slower than their spin rate.
As a result, all electromagnetic and radio waves get amplified and are picked up by spacecraft hovering in space. These electrons also create auroras in the ultraviolet spectrum.
NASA will extend two of its planetary discovery missions including its Juno which detected the ‘cyclotron maser instability (CMI)’ from Ganymede in the first place.
Like Earth, Ganymede has a liquid iron core that generates a magnetic field, though Ganymede’s field is embedded within Jupiter’s magnetic field. That sets up an interesting dynamic with telltale visuals – twin bands of glowing aurora around Ganymede’s northern and southern polar regions. As Jupiter rotates, its magnetic field shifts, causing Ganymede’s aurora to rock.
NASA Planetary Science Division Director Jim Green called the finding ‘an astounding demonstration’.