2021, June 23: Mars in the Beehive

June 23, 2021:  Red Planet Mars appears to be in the Beehive this evening.  For clarity, it’s in the Beehive star cluster.  While low in the sky and in an unfavorable observing location, take a look with a binocular before the planet and the cluster set.

by Jeffrey L. Hunt

This evening as the sky darkens, brilliant Venus sparkles in the west-northwest.  Mars has dimmed considerably and is best found with a binocular, although it is in easy range of the unassisted eye.  The Red Planet is 11.4° to the upper left of Venus.

If you extend your arm and make a fist, the distance from your pinky knuckle to your thumb knuckle is about 10°.  To locate Mars, extend your arm and place Venus near one knuckle.  Tilt your fist at an angle to the upper left.  Mars is in the region of the other knuckle. 

The binocular is handy in noticing that Mars is in front of a smattering of stars.  This is known as the Beehive star cluster or the Praesepe – the manger.

When the cluster is higher in the sky and the moon is not so bright, it can be seen without an optical assist.  It is a good gauge of the clarity of the sky.   In early writings, it was noted as “little cloud” or “little mist.”

The star bundle is among the dim stars of Cancer, about halfway from Pollux to Regulus.  It’s a large gap between the two stars, but the cluster is easily located. Quite simply find the two brighter stars and look halfway between them.

This evening the constellation and cluster are quite low in the western sky.  The passage of Mars nearby is worth noting and merit the look through a binocular.

The Beehive and the famous Pleiades are known as galactic or open star clusters.  They are found in the plane of the galaxy, unlike the globular star clusters that have been recently highlighted on these pages.  The open clusters are chemically different from the globulars and their ages are considerably different. The open clusters have space between the stars, while the stars in the globular clusters seem crowded, like they are shoulder to shoulder in a waiting line.

Note two stars in the same binocular field with Mars and the Beehive.  They are Asellus Borealis, “the northern little ass” (γ Cnc on the chart) and Asellus Borealis (δ Cnc), “the southern little ass.”  If there’s a manger, then there must be animals.

Mars moves through the region again and appears in front of the cluster on June 2, 2023.

Articles and Summaries

• Venus as an Evening Star
• Venus Evening Star (Summary)
• Mars during 2021 (Summary)
• Planets during June 2021