The "Dagwood Sandwich" Moon. Earlier models of Ganymede's oceans were based on the assumption that the existence of salt didn't change the nature of liquid very much with pressure. However, Dr. Vance and his colleagues found, through laboratory experiments, that salt does increase the density of liquids under the extreme conditions hidden deep within Ganymede and similar icy moons with subsurface bodies of water. Imagine adding table salt to a glass of water. Instead of increasing in volume, the liquid will actually shrink and become denser. The reason for this is that salt ions lure water molecules.
"Makemake is in the class of rare Pluto-like objects, so finding a companion is important. The discovery of the moon has given us an opportunity to study Makemake in far greater detail than we ever would have been able to without the companion," Dr. Parker continued to explain.
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.