If you have a medium sized telescope, you might like to watch Saturday night as Europa’s shadow crosses the face of Jupiter. Europa is one of Jupiter’s four largest Moons, commonly referred to as the Galilean moons after their discoverer Galileo Galilei. I find that with good seeing conditions, my eight inch dobsonian telescope and a high power eyepiece, I can easily view the black shadows of Jupiter’s largest moons on its cloud tops.
![17_December_2011_Europa_shadow_transits_Jupiter](http://nightskyonline.info/wp-content/uploads/2011/12/17_December_2011_Europa_shadow_transits_Jupiter-300x225.jpg)
According to Astronomy 2011, Europa’s shadow begins its transit of Jupiter’s disc at 9.57 pm AEST (10.57 pm Daylight Savings Time) on Saturday 17 December and exits Jupiter’s disc at 12.22 am AEST (1.22 am Daylight Savings Time) on Sunday morning 18 December 2011. The above screen shot produced using the highly recommended Sky Safari Plus Apple Ipad app shows just how small the shadow will be compared to Jupiter. Look near the top right hand side of Jupiter to locate the tiny black shadow in the image.
To find Jupiter, just look above the North Western horizon between the times listed above. Jupiter will be the brightest star you will immediately notice.