Moon and faint Cancer on March 6

On March 6, 2020, the bright waxing gibbous moon shines in front of Cancer the Crab, the faintest constellation of the zodiac. Although the moon marks Cancer’s place in the sky on this night, the moonlit glare will make Cancer tough to see.

We’re showing it to you now so that you can notice the stars to either side of the moon on March 6, and find these stars again when the moon has moved away. Then – if you have a dark sky – you can find Cancer and its hidden gem, the Beehive star cluster.

Star chart showing stars and clusters.

The constellation Cancer via the International Astronomical Union (IAU). On a dark night, look for the Beehive star cluster (M44) to make a triangle with either bright Gemini star – Castor or Pollux – and the bright star Procyon.

You shouldn’t have much trouble spotting some bright stars on either side of Cancer, along the zodiac. The Gemini stars, Castor and Pollux, lie to the west of tonight’s moon whereas the star Regulus, the brightest in the constellation Leo the Lion, shines to the east of tonight’s moon.

As the Earth spins beneath the heavens throughout the night, going from west to east, the moon, Cancer, the Gemini stars and Regulus will appear to move westward across the sky.

The moon will set in the west in the wee hours before sunrise March 7.

Read more: Cancer? Here’s your constellation

Diagram of constellation Cancer with location of Beehive cluster marked.

There’s a faint star cluster in Cancer, called the Beehive. In a dark sky, once the moon moves away, you can glimpse it with the eye alone. Read more about the Beehive.

Bottom line: The bright waxing gibbous moon shines in front of Cancer the Crab, the faintest constellation of the zodiac, on March 6, 2020. Notice Castor and Pollux to the west of the moon, and Regulus to the east of the moon. Then come back when the moon is gone to find Cancer between these stars.

Bruce McClure