Monday June 17, 2019:
Jupiter and its four major moons: (left to right) Ganymede, Jupiter, Io, Europa, and Callisto.
Peering into the night sky, we spot a familiar bright object this time of year. This particular celestial object happens to be the largest and 5th planet from the Sun, Jupiter. In photo above, Jupiter appears with its four major moons, the Galilean moons. These moons were discovered when Italian astronomer Galileo Galilei first used the telescope in the early 17th century. The Galilean moons are Ganymede, Io, Europa, and Callisto. Ganymede is the largest moon in the solar system, bigger than Mercury, and the only moon to have a magnetic field. If Ganymede was orbiting the Sun instead of Jupiter, it would of been classified as a planet. Io is the densest moon and most volcanic object in the solar system. It has more 400 active volcanoes sending out plumes of sulfur (S) and sulfur dioxide (SO2). Europa is likely to have a global subterranean salt water ocean. That ocean is surrounded by thick ice covering. (Other moons such as Ganymede, Titan (Saturn), and Enceladus (Saturn) are suggested to have similar subterranean oceans.) Callisto is just heavily cratered, but maybe there is more to it, so stay tune for further discoveries in the Jupiter system. Jupiter has a system of 79 moons including the Galilean ones. Our solar system is a fascinating place.
Inspire to imagine, explore, and capture the moment.