Blog de Puree

Last week on Friday was a great night for viewing the night sky. That afternoon, when I came home from work, my neighbor’s daughter came over in a state of excitement because her social studies teacher told her that one could see some of the moons of Jupiter, and she asked if I would set up the Dobsonian telescope. (Sure, twist my arm.)

At approximately 9:00 p.m., the only light in the area was the glow of the streetlights, most of which were partially blocked by street lights. We set up the telescope in my neighbor’s yard and aimed it due south, where we could see the solar system’s largest planet with the naked eye. It looked like a slightly reddish blip. Until we peered through the lens of the scope.

Jupiter was clearly visible and you could make out the colored striations that are wind storms continually howling through the planets atmosphere. And the teacher was right. In a straight line were four of Jupiter’s moons, two on each side of the planet. All four were large white circles, not nearly as big as the planet, but easy to make out as they seemed to hang on each side as if the were attached by an invisible wire, like a mobile hanging at a science museum.

This was a first for me—seeing Jupiter’s moons—and it was pretty exciting. Although we could not identify which moons they were, it was satisfying enough to see the moons of another planet in the solar system. However a little research uncovered more information.

This photo is close to what we actually saw, but eliminate the purple circle and make Jupiter a bit larger and in better focus.

The moons, if I understand some of the websites and illustrations correctly, are identified from left to right as Europa, Callisto, Io and Ganymede. Known as the Galilean moons, they are the largest of Jupiter’s moons and were discovered by, you guessed it, Galileo Galilei. Here is a quick rundown of each moon.

Europa: The smallest of the four moons, the smoothest object in the solar system, surface is ice with water presumed to be underneath. It is hear that space efforts are being directed to discover other forms of life in the solar system.

Callisto: The second largest moon, one of the most heavily cratered satellites in the solar system, also contains a lot of ice and water and has an atmosphere carbon dioxide.

Io: The fourth largest moon in the solar system and the most volcanically active. Recent data asserts that it has its own magnetic field and has an atmosphere of mostly of sulfur dioxide.

Ganymede: The largest moon in the solar system, the only moon that has a confirmed magnetic field, composed of silicate rock and water ice, and has a small oxygen atmosphere.

In addition to Jupiter’s moon sighting, my neighbor’s daughter dazzled us by picking out the Cassiopeia constellation. She turned around to the North, pointed up and said, “Hey, there’s Cassiopeia!” I confirmed this with my star chart and her dad was completely blown away. The smile on her face was a light year wide. It completely rocks when kids enjoy astronomic discovery that you can help facilitate, and made the night that much more satisfying.