This time the Moon will cross not a big planet but big Antares, one of the two brightest red supergiant stars in the sky (the other being Betelgeuse, which is too far from the ecliptic for the Moon ever to occult it). Mark your celestial calendar for March 2, 2005, with a reminder to set your alarm clock for early Thursday morning, March 3rd. For nearly all of the North American continent, the last-quarter Moon will be hanging in plain view in the southeast or south when it covers and uncovers Antares.
As usual when the Moon is waning, the star will disappear behind the Moon’s bright limb, where you’ll need a telescope to follow it as it creeps up to the glary edge of the brilliant lunar terrain. Antares will hang right on the edge for a few seconds — a fire on the Moon then vanish instantly, or nearly so.More spectacular will be Antares’ reappearance roughly an hour later out from behind the Moon’s dimly earthlit dark edge. This event should be visible to the naked eye in a dark sky — if you’re staring at the Moon at exactly the right moment. Of course, binoculars or a telescope will give a far better view. (For Easterners the reappearance happens after sunup, but even so you’ll have no trouble finding the Moon with the naked eye and seeing Antares snap into view in the blue sky with a telescope.)
Sky & Telescope has prepared custom predictions for 340 cities in the United States, Canada, and Mexico. For more about observing the occultation, including how to make scientifically useful observations, see the March issue of Sky & Telescope, page 67.