September 20, 2010
I can just imagine how excited I would have been for this event when I was a young kid and a member of the Junior Astronomy Club at the American Museum of Natural History in New York City. Wait a second there, young Seymour — I’m STILL excited about it! Here’s what’s going on this evening: Jupiter, the biggest planet in our solar system, will be overhead in the night sky at midnight, shining brighter than everything except the Moon.
Jupiter and Earth each revolve around the sun in their respective orbits. Earth takes 365 days, one Earth year, to make one revolution. It takes Jupiter nearly 12 Earth years, 4330 Earth days, to make one revolution around the sun. That means that the two planets are rarely very near each other in their orbits. But not tonight. Earth and Jupiter are the closest together in space that they will be for the 12 years, until 2022.
If you look through even a small telescope or a pair of high-magnification binoculars you should see Jupiter’s four big moons (called the Galilean moons because of their discovery in 1610 by the great scientist Galileo). Galileo used a small telescope that is about 20x magnification.The four moons he discovered are name Io, Europa, Ganymede and Callisto.
Here’s a photo of Jupiter and the shadow of Io on the surface of the planet. This was taken by Anthony Wesley of Australia (he used a much higher magnification, so you won’t be able to see Jupiter quite like this).
Posted by: Seymour Simon
