Cancer the Crab is a faint and inconspicuous constellation that can be identified this month by the presence of Mars in its borders. It is the least notable of any of the constellations in the zodiac.
Greek mythology has it that Hera — who, as the wife of Zeus, was the queen of all the gods — sent the crab to harass Hercules in his battle with the many-headed monster Hydra. Hercules crushed the crab beneath his heel, and as a reward for its bravery, Hera placed the crab in the heavens as a constellation.
Cancer is most noted for its neighbors that include the Beehive star cluster and the stars Regulus, Castor, Pollux and Procyon. Cancer does have two binaries each consisting of a yellow and blue component.
Focus on the planets
Mercury appears low on the western horizon about a half-hour after sunset late in the month. On the last day of the month, Mercury appears to the immediate lower right of Venus.
Venus opens March low in the west at sunset but gradually climbs higher as the month progresses.
Mars is high in the southeast as darkness falls where it appears as an orange-yellow point forming a line with Castor and Pollux of Gemini. On March 1, Mars is brighter than any star but Sirius and then fades as the month wears on.
Jupiter does not make an appearance until month’s end, when it appears very low on the eastern horizon about a half-hour before sunrise.
Saturn rises in the east at twilight, shines high in the southeast at midnight and sets in the west at dawn. Midnight is the best time to view Saturn’s rings, which are already beginning to narrow.
Uranus is to the upper right of Venus but will be impossible to spot in the bright sky.
Neptune is also lost to view in March.
1 Sunrise, 6:14 a.m.; sunset, 5:22 p.m.
7 Moon in last quarter, 10:43 a.m. Check out the southeast pre-dawn sky for the moon to the immediate left of Antares.
12 The sun enters Pisces on the ecliptic. The moon is at apogee, or farthest distance from Earth.
14 This is the second Sunday of March so it is time to set clocks forward an hour as we enter daylight saving time.
15 New moon, 5:02 p.m. This is the Ides of March, a bad day for Julius Caesar.
16 Venus shines on the western horizon at dusk with the thin crescent moon to its right.
17 St. Patrick’s Day. One almanac says this is the day to plant your peas but that may be optimistic in Maine.
20 Vernal, or spring, equinox, 1:33 p.m. Today the sun crosses the equator to re-enter the Northern Hemisphere. The sun enters the astrological sign of Aries but astronomically has only just entered Pisces. Tonight the moon passes very close to the Pleiades star cluster with brilliant Aldebaran to the upper left.
23 Moon in first quarter, 6:59 a.m.
24 Look for orange-red Mars east of the moon tonight.
28 The nearly full moon is at perigee, or nearest approach to Earth, today. Look to the southeast about two hours after sunset for Saturn slightly to the lower left of the moon.
30 Full moon, 10:25 p.m. The full moon of March is known as the Sap Moon or Worm Moon. This year it is also the Paschal Moon or the first full moon after the spring equinox.
31 Sunrise, 6:19 a.m. sunset, 7:01 p.m.