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.
Titan's atmosphere is approximately 95% nitrogen. However, in a way that dramatically differs from Earth's own mostly-nitrogen atmosphere, Titan's atmosphere has very little oxygen. Indeed, the remainder of Titan's atmosphere is almost entirely composed of methane--along with small qunatities of other gases, such as ethane. At the extremely cold temperatures that are found at Saturn's great distance from the heat of our Star, Titan's methane and ethane can accumulate on its icy surface to form pools of liquid.
Saturn is the smaller of the two gas-giant planets, twirling around our Sun, in the outer regions of our Solar System--far from the delightful warmth of our lovely incandescent roiling gas-ball of a Star. Jupiter is the larger of the duo of gas-giants dwelling in our Solar System, as well as the largest planet in our Sun's bewitching family, which is composed of eight major planets, an assortment of moons and moonlets, and a rich menagerie of smaller objects. Saturn is the second-largest planet in our Solar System--and probably the most beautiful.