Following the Path of the Moon
Friday evening, look in the wake of the setting sun low in the west-northwest for the nascent crescent moon and Mercury. Mercury is just a few degrees to the upper right, but both are so close to the horizon that you may need binoculars and you won’t have long. Within 90 minutes of sunset Mercury is gone. And that window is shrinking each day. Mercury is surprisingly bright — equal to any star. But don’t confuse its white glow with the much brighter and golden hue of Jupiter, 20 degrees higher.
By sunset Saturday, the moon has climbed well above the horizon, leaving Mercury in the dusk. Now the thin crescent is just seven degrees below Jupiter, easily the brightest object other than the moon. The moon, Jupiter and Pollux higher still form a near-straight line.
Sunset Sunday finds the waxing crescent moon well positioned in the west. Jupiter shines 10 degrees to its right, while below and to the left, making a wide triangle, is the first-magnitude star Procyon. The eighth-brightest star in the heavens, Procyon is one of two bright stars in the constellation Canis Minor, the Little Dog.
Monday the moon is amid the dim stars of Cancer. Look a few degrees to the right of the moon for a dim patch of light at the constellation’s center. Unlike the sharp, clear light of a star, the hazy glow you’re seeing is the combined light of hundreds of newborn stars within the Beehive Cluster 570 light years away. While our own sun is 4.5 billion years old, the stars of the Beehive Cluster are only 600 million years old, mere infants in the life of a star. Binoculars are enough to distinguish dozens of these lights; a modest telescope reveals many more.
Tuesday and Wednesday the moon is several degrees to either side of Regulus, the blue-white heart of Leo the lion. Regulus marks the dot at the base of what looks like an inverted question mark, called the Sickle of Leo.
As twilight turns to darkness, Mars glows like an ember in the south. Far to the lower left is Spica. The red planet sets around 3am.
Saturn shines in the southeast at sunset, is high in the south around midnight and sets in the west around 4:30am. The ringed planet is flanked by the two brightest stars of Libra — both second-magnitude — Zubenelgenubi and Zubeneschamali.
In the hour before sunrise, Venus appears low in the east. At –4 magnitude, there’s no confusing the Morning Star for anything but an airplane or satellite — except that it holds steady in place until daybreak.