Sunday, December 20, 2009

A winter solstice treat: the Moon and Jupiter

Monday evening, December 21, the Moon will be positioned next to bright Jupiter in the southwest sky just after sunset. Try viewing this combination through binoculars. What can you see? The binoculars should reveal larger craters on the lunar surface along with mountains. Jupiter will show three starlike moons right next to it (one on its left and two on the right) before 7:20 and four after 7:20. Its moon Io, which is slightly smaller than our Earth's moon, moves out of eclipse at 7:20. It take a few minutes to come into view on the left side of Jupiter.

Such is our view from Earth ...

Monday, December 14, 2009

Bright Jupiter and dim Neptune

This week, easy-to-find Jupiter slides past distant Neptune. You'll need binoculars to see this event, though. Look towards the south-southwest at 7:00 p.m. for bright Jupiter. It is easily the brightest object in that area of the sky.

Neptune is dim, fainter than the three stars that lie almost in a row near Jupiter's position on the 16th. On December 21, Jupiter is at its closest approach to Neptune. The moon may interfere with observations on the 20th and succeeding nights, so try spotting the planetary pair before this Saturday.

Such is our view from Earth ...

Friday, December 4, 2009

Elusive Mercury

Without a doubt, the most difficult to spot of the "bright" planets is little Mercury. It is always close to the sun, most times lost in the solar glare either directly after sunset or right before sunrise. For most of December, curious skywatchers who have a low southwestern horizon can find Mercury close to the horizon at about 5:40 p.m. The best dates to try are those around December 18. On the 18th, the thin crescent Moon floats just above the elusive world. Bring out the binoculars for a better view.

A couple days after Christmas, Mercury drops rapidly towards the sun. By January 4th, it passes between the Earth and the Sun.

Such is our view from Earth ...