The new findings are an independent line of evidence that hydrothermal activity is taking place in the subsurface ocean of Enceladus. Earlier results, published in March 2015, indicated hot water is interacting with rock beneath the sea of this distant moon. The new discoveries support that conclusion and add that the rock appears to be reacting chemically to produce the hydrogen.
Jupiter, along with its beautiful ringed sister planet, Saturn, are the gas-giant duo of our Sun's family of eight major planets. The other two giant planets--that dwell in our Solar System's outer limits--are Uranus and Neptune. Uranus and Neptune are classified as ice giants, because they carry within them larger cores than Jupiter and Saturn, as well as thinner gaseous envelopes. Jupiter and Saturn may (or may not) contain small, hidden cores, that are heavily veiled by extremely massive, dense gaseous envelopes.
Comets are actually bright, streaking invaders from far, far away that carry within their mysterious, frozen hearts the most pristine of primordial ingredients that contributed to the formation of our Solar System about 4.6 billion years ago. This primeval mix of frozen material has been preserved in the pristine "deep-freeze" of our Solar System's darkest, most distant domains. Comets are brilliant and breathtaking spectacles that for decades were too dismissively called "dirty snowballs" or "icy dirt balls", depending on the particular astronomer's point of view. These frozen alien objects zip into the inner Solar System, where our planet is situated, from their distant home beyond Neptune. It is generally thought that by acquiring an understanding of the ingredients that make up these ephemeral, fragile celestial objects, a scientific understanding of the mysterious ingredients that contributed to the precious recipe that cooked up our Solar System can be made.