In this movie, we see Mars as it moves against the stars of the Zodiac between May 1, 2003, and December 31, 2003.

Starting in May, Mars moves eastward through the constellation of Capricornus. At the end of June, Mars seems to come to a halt and begin moving west-to-east in the constellation of Aquarius. It continues its backward, or "retrograde," motion until the end of September, when it resumes its normal west-to-east motion.

Mars doesn't actually stop and go backward in its orbit around the Sun. Its apparent motion is due to the fact that we here on Earth orbit the sun faster than Mars does. From our perspective, as we catch up and pass the Red Planet, it just appears to be going backward. (If you’re passing cars on the freeway, you can see the same sort of thing happen: from your point of view, the slower cars may momentarily look as if they’re going backward.)

Notice that Venus starts out to the east of Mars in May, and ends up to the west of Mars at the end of December. The little dots on Mars’ path mark the planet’s position every 10 days. Yes, that is the Moon you see speeding by about once every month.