With the help of the Hubble Space Telescope, scientists found that one of Jupiter’s Moon, Ganymede, houses an ocean beneath its icy exterior. NASA is hopeful that this breakthrough will raise the possibility of life on other components of the Solar System.
The first data regarding the existence of an ocean beneath Ganymede’s surface was recorded by the now-difunctioned Galileo spacecraft which explored Jupiter and its moons between 1995 and 2003.
Scientist said in a statement that a lot of analysis and many calculations were necessary in order to reach this conclusion. Ganymede is similar to Earth in terms of having a core made of liquid iron that generates a magnetic field which is an integral part of Jupiter’s magnetic field. The interaction between the two magnetic fields creates amazing visual phenomena like the twin bands of glowing aurora surrounding Ganymede’s northern and southern poles.
Jupiter’s magnetic field changes its position as the planet rotates causing Ganymede’s aurora to move from side to side. The team analyzed the motion and discovered it was much lower that it was theoretically predicted.
With the help of computer models, the researchers found what was opposing to Jupiter’s magnetic influence – “a salty, electrically conductive ocean beneath the moon’s surface”.
Joachim Saur, a geophysicist at the University of Cologne in Germany came with the explanations and proper metaphors:
“Jupiter is like a lighthouse whose magnetic field changes with the rotation of the lighthouse. It influences the aurora. With the ocean, the rocking is significantly reduced.”
In order to be completely certain that there wasn’t anything else that could affect how Jupiter’s magnetic field influences Ganymede’s aurora, they used more than 100 computer models. The team also repeated the seven-hour ultraviolet observations made by the Hubble telescope. Both of Ganymede’s auroras were analyzed.
According to Jim Green, Director of the NASA Planetary Science Division, their methods of analysis were very interesting as they managed to find “a new approach to look inside a planetary body with a telescope.”
Ganymede is just one of a series of moons in the outer solar system that presents subsurface water. On Wednesday March 11, another team reported they detected the presence of underground hot springs on the icy Enceladus, one of Saturn’s moons. The presence of water was also detected on Europa and Callisto, two other Jupiter moons.
Image Source: UT Astrophysics