Tonight’s bright waxing gibbous moon – February 28, 2015 – will be bright enough to erase many stars from the blackboard of night. Even so, three stars should be brilliant enough to withstand tonight’s moonlit glare – the Gemini stars, Castor and Pollux, plus Procyon the Little Dog Star. In late February and early March, the moon passes south of Castor and Pollux, and north of Procyon, the brightest star in the constellation Canis Minor the Lesser Dog.
And there’s one more object you’re sure to notice near the February 28 moon. That dazzling object to the east of tonight’s moon is the planet Jupiter. The king planet is far brighter than any star (except our sun). Jupiter will follow the moon, Castor, Pollux and Procyon westward across the sky, until the moon and three accompanying stars set in the west during wee hours of the morning on March 1.
Look for the moon and these stars to reach their high point for the night somewhere around 9 p.m. local time (that’s the time on your clock, no matter where you live around the globe).
If you live in the Southern Hemisphere, please keep in mind that you’ll see the sky scene upside-down in your northern sky. In other words, you’ll see Procyon at top and the Gemini stars beneath the moon.
No matter where you live worldwide, however, the moon routinely passes to the south of the Gemini stars, Castor and Pollux, and to the north of Procyon each month. As the moon travels eastward in front of the constellations of the Zodiac, it goes through this stellar passageway in periods of about four weeks.
The dark side of the waxing moon always points eastward or in its direction of travel. Although the moon and stars go westward during the night because of the Earth’s rotation, the moon actually goes eastward relative to the backdrop stars (and planets) because of the moon’s orbital motion, as illustrated on the sky chart below.
Bottom line: On the night of February 28, 2015, watch the moon pass to the south of the Gemini stars and to the north of Procyon. Then watch over the following nights as the moon edges toward the king planet Jupiter.