On the mornings of September 30 through October 2, Mars appears to move past the Beehive star cluster in Cancer. The fainter constellation occupies the region between the Gemini twins (Castor and Pollux) and Leo, with its bright star Regulus. At 4:30 a.m. on these mornings look east. Regulus is near the eastern horizon with the Gemini twins high in the sky. Mars appears between in a part of the sky with few bright stars. Mars is distinctly reddish. Because of its distance from Earth, Mars looks like a brighter star. It will be the brightest object between Leo and Gemini.
To get a sense of the stars in that part of the sky, the moon passes through this region the week before Mars passes the star cluster. See the September 2011 summary.
Away from city lights, a smudge of light appears near Mars. This is the star cluster.
Catalogued as M44 and NGC 2632, the Beehive star cluster can be seen as individual stars through binoculars. The optics will also reveal Mars’ color. The cluster is about 500 light years away and it has at least 300 stars.
In Robert Burnham’s Celestial Handbook he writes that the star cluster was used in ancient times as a weather indicator. Aratus and Pliny have both stated that the invisibility of the [star cluster] in an otherwise clear sky was considered to forecast the approach of a violent storm (p 345).
The star cluster is part of Cancer, forming the starry backdrop for the motion of the objects in the solar system. Since it’s difficult to perceive distances, the planets appear to move through or among the stars, but the stars and planets are very far apart. About every year or so a bright planet appears near the cluster. A year from now, Venus appears near the cluster, followed by a return visit in 2013. Mercury visits August 2013, followed by a return visit by Mars in early September.
The chart above shows Mars and the star cluster as they would be seen through binoculars on September 30 – October 2, 2011. On October 1, Mars appears hidden among the stars of the cluster, a spectacular sight.
Categories: Sky Watching