The movie below shows how Jupiter, Venus & Mercury will look at 5pm in the evening sky everyday throughout December 2008, as produced using the excellent (& free!) planetarium software Stellarium.

At the start of the month, the brighter Venus is to the left of Jupiter - both are easily visible with the unaided eye in the evening twilight. Between 4pm and 5pm is the best time to look.

As December progresses (see the date in the top left corner), Venus gets higher and higher in the evening sky. As the Earth orbits around the Sun, it is moving to the opposite side of the Sun to Jupiter - which is why Jupiter appears to be moving towards the Sun. Just after Christmas, Mercury comes into view as well.

New Year's Eve is the highlight, however, with Jupiter and Mercury being VERY close together in the twilight sky, as well as the Moon and Venus!

This movie shows how we will see the planets "dance" during December (2008). First off, we see the view that we will have when we look towards the South-West. The movie then plays again, this time retaining the 'old' positions super-imposed so we can see exactly where the planets have moved from. Finally, these two scenes are repeated for convenience.

To understand why the planets are moving around as they do, take a look at the view from above...

This image was produced using the free Celestia software. The yellow arrow indicates which way all the planets orbit around the Sun, and note that the planets closer to the Sun orbit much quicker than the planets further out. Mercury wizzes around the Sun in just 88 days; Venus in 225 days; the Earth in 1 year; and Jupiter takes almost 12 years to orbit the Sun!

From above, we can see that, as the Earth orbits the Sun, Jupiter begins to be hidden by the glare of the Sun as the Earth moves to the opposite side, while Venus & Mercury become easier to see as they get further away from the Sun.

After seeing all this movement, it is hardly surprising to learn the origin of the word 'planet' - it's ancient Greek meaning wanderer!