With the reinvention of the telescope to magnify up to twenty-times came the discovery of four new satellites that orbit the Jovian planet Jupiter. These four moons aer currently being called the Galilean Moons in honor of the genius who discovered them, Galileo Galilei. The moons individual names are Ganymede, Io, Calisto, and Europa.
-wikipedia.org-
As far as we can tell, through Galilei's calculations, the moons are, to coin a word, humongous! The greastest of them all, Ganymede, is even larger than the first planet, Mercury. And the rest of them are all larger than our dear friend, the Moon. Not much else is known
about these monstrous (is that another new word? 2 for 2!) satellites except that they are highly reflective and so Galileo has assumed that ice has accumulated on many of their surfaces. They appear to be very cratered as well. Perhaps in due time we can know more about them, may we suggest a "voyage" to the Jovian planet. As always, we will keep you posted on any new information we might have.