Keep your letter short, focused, and interesting. In general, letters should be under 200 words, 150 or less is best; stay focused on one (or, at the most, two) main point(s); and get to the main point in the first two sentences. If possible include interesting facts, relevant personal experience, and any local connections to the issue.
Jupiterâs Moons â 67. Jupiter is swarming with at least 67 moons in orbit around it, the largest number of natural satellites around any of the planets. Jupiterâs 4 largest moons; Ganymede, Callisto, Io and Europa are known as the Galilean Moons, named after their discoverer Galileo Galilei.
Ganymede is the largest and most massive moon in the Solar System. Its diameter of 5,268 km is 0.41 times that of Earth, 2% larger than that of Saturn's Titan (the second-largest moon), 1.08 times Mercury's, 1.09 times Callisto's, 1.45 times Io's and 1.51 times the Moon's.