Tonight is a great night to get outside and look up (assuming you are not in the cold party of the country!) The early show starts right after sunset. The first quarter Moon passes near Jupiter tonight (about six degrees away ballpark). Find the Moon...the bright thing near it, that's Jupiter. If you have binoculars or a telescope, Jupiter's moons are easily visible.
The real challenge occurs right after sunset. Mercury and Mars are VERY low in the southwest. You will need a good flat horizon, very clear skies and a sharp eye to catch them. They are only one degree apart (about the width of your pinky held at arms length). Here's a chart to help, but you have only about 30 minutes after sunset before they are gone!
For the late night owls, one of the best meteor showers of the year, the Geminids, peaks tonight. The Geminids are just as good if not better than the more famous Perseids in August. They are also much colder for most of the northern hemisphere! Although it is better to go out really late at night, due to Earth's tilt, Gemini rises by 10pm local time over most of the continental U.S. meaning you can get good meteor counts earlier than for most showers. Of course, you want to get rid of the light from that pesky Moon to get the best view. The first quarter Moon sets around midnight local time. The Geminids are fairly slow moving (as far as meteors go at least) and that makes them a little easier to observe.
The Geminids have a fairly broad distribution, so if you miss them tonight, there will still be quite a few around the next couple of nights as well.
Reprinted from the Half-Astrophysicist Blog.