NASA has made the discovery of the decade this week, a speculation by scientists since the 1970’s has been that Ganymede could have an ocean has finally been confirmed. The first pieces of evidence were collected by the Galileo spacecraft in the early 2000’s which left too much ambiguity in the data for NASA’s scientists to simply let go of.

So how did NASA find oceans on the surface of the Ganymede, the spacecraft responsible for collecting the data was the hubble. What the hubble observed over time was the aurorae of the atmosphere. The aurora is the colorful result of supercharged particles interacting with the atmosphere, very similar to the Northern Lights we see on earth. It’s simple existence of aurorae doesn’t exactly mean that there is an ocean present on the moon but its behaviour does point towards the fact that its being changed by one.

So what triggered the fact that there’s an ocean present relative to the aurora, its the fact that the aurora would move back and forth across about six degrees as it orbited Jupiter, but the fact that it stayed fairly stable meant that there was a presence of salty, electrically conductive oceans which was locking the aurorae. The UV spectrum analysis from the hubble made it possible to collect all this information that lead to this conclusion.

While its great that there is an ocean present on the moon and that it has its own magnetic field just like the earth, it might not be the best place to be looking for life at the moment. From surface maps it seems the oceans are a good 100 miles below the surface which is mainly ice and that it wouldn’t be possible to send an unmanned to do further research. Ganymede is definitely in a viable list of places to find life but not on top of that list especially because due to its atmosphere and climate it wont be able to support a hydrothermal system.