Ganymede: Ganymede is both the largest moon of Jupiter, our Solar System's planetary behemoth, as well as the largest moon in our entire Solar system. Observations of Ganymede by the HST in 2015 suggested the existence of a subsurface saline ocean. This is because patterns in auroral belts and rocking of the magnetic field hinted at the presence of an ocean. It is estimated to be approximately 100 kilometers deep with a surface situated below a crust of 150 kilometers.
Similarly, in Norse mythology, Mani is the male personification of the Moon. Mani wanders across the sky in a horse and carriage, perpetually pursued by the Great Wolf Hati who catches him at Ragnarok--which is the "Twilight of the Gods," and the end of everything, in Norse mythology--that is, until it all begins anew.
When President John F. Kennedy stated in 1960's that the US will go to the moon in less than a decade, most people were extremely skeptical. The reason for this stemmed from the fact that USSR had shown more accomplishments in the space race after the launch of Sputnik, which was the world's first satellite. Naturally, the skepticism was unfounded, since the US put all of its efforts in to the Moon program as billions of dollars were put in to it. The development of the Saturn rocket as well as the development of the Apollo lunar module took less than a decade, since the whole heart and soul of the American public was put into the Lunar program. Even the various tragedies such as the loss of Astronauts in the Apollo fire tragedy didn't deter the public. As a result, 1969 was an important year in the human history as mankind stepped into Lunar soil for the first time. Sadly, the program was discontinued and since the 1970's, no man has even stepped into the Lunar soil ever again.