In its 29.5-day-long journey around the Earth, the moon passes in front of all of the planets but relatively few stars that are bright enough to be visible close to the moon. The two brightest stars are Regulus in Leo and Antares in Scorpius. Wednesday night, Sept. 23, the 5-day-old moon will be close to Antares.

Antares is Greek for ?opposite Mars,? referring to its deep red color, resembling Mars. At? present Antares is close to minimum brightness, which also means that it is at its reddest.

The problem with this conjunction between the moon and Antares is that Antares is rapidly disappearing into the sunset, so that the trick is to observe it before it gets too low in the sky.

Because the moon is moving from right to left across the sky as the Earth?s rotation carries the stars from left to right, the distance between the moon and Antares gets smaller the farther west you are in North America. On the east coast, let?s say Boston, at 8 p.m. E.D.T., the moon and Antares are 3? 50? apart. On the west coast, in Seattle, at 8 p.m. P.D.T. , they are only 2? 10? apart.

(Your fist on an outstretched arm measures about 10? of sky.)

What happens further west, out over the Pacific Ocean? The moon actually passes in front of Antares, in what is called an occultation. Such occultations of bright stars are relatively rare, and to see them stargazers must be at the right place at the right time. Often the moon passes just above or just below a star, and often occultations happen on the ?wrong? side of the Earth.

A conjunction between the Moon and a bright star or planet is something which requires no optical aid. It can be enhanced with ordinary binoculars, but these aren?t necessary. So, step outside Wednesday evening around 8 p.m. your local time and look to the southwest.

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This article was provided to SPACE.com by Starry Night Education, the leader in space science curriculum solutions.