Break out those binoculars! In all of March, early risers will be rewarded with views of a pair of planets within a single binocular field; two pairs in separate fields during the first few days of the month; or even three planets within a single field. Background stars marking the head and tail ends of Capricornus provide additional interest.
With the start of daylight saving time on March 13, viewing times suddenly shift an hour later, becoming more agreeable for folks averse to predawn consciousness.
Bright Venus and faint Mars linger close together in the southeast an hour before sunup throughout March. They’re 5 degrees apart on March 1, within 4 degrees March 12 to 19, and widening to 6 degrees apart by March 31. Look for Mars to the lower right of Venus for most of month, climbing directly to its right during the closing week.
At the start of March, bright Mercury is getting lower each morning, while Saturn, emerging from solar conjunction, climbs higher daily. On March 2, Mercury (magnitude -0.1) passes within 0.7 degrees south (to the lower right) of fainter Saturn (magnitude +0.8). Look for the pair very low in the east-southeast, within 23 degrees to the lower left of Venus about 40-45 minutes before sunrise. Binoculars give a fine view of the conjunction on March 2, and of the widening pair for a few additional mornings as Mercury sinks into brighter twilight.
Visualize why that happens: In March: Spaceship Earth is heading in a direction a few degrees above, or to the upper left, of Antares in the southern morning sky. As seen from “above,” or north of the solar system, all the planets trace out their orbits in a counterclockwise direction. Mercury, an inner planet, goes faster than Earth. Already on the far side of its orbit, Mercury will pass superior conjunction, invisible on the far side of the sun, on April 2. Saturn was at conjunction on the far side of the sun on Feb. 4. Although distant Saturn is going around the sun in the same direction as Mercury, Earth’s motion is faster than Saturn’s, causing the sun to shift from Aquarius into Pisces in March—so Saturn, left behind in Capricornus, rises farther ahead of the sun each morning. Earth will eventually overtake Saturn, on Aug. 14—and it then will appear at opposition and be visible all night.
As Venus circles around the sun into the part of its orbit more distant from us, telescopes show the disk shrinking in size while its phase waxes. In transition from crescent to gibbous, the planet is half-illuminated when near its greatest angular separation of 47 degrees west of the sun, on March 20.
Follow the moon in morning twilight from March 16 or 17 through March 29. After passing full on March 18, the waning gibbous moon appears 5 degrees from Spica on March 20, and passes just 2 degrees north of Antares, heart of the Scorpion, on March 23. The crescent moon will appear 5 to 7 degrees below a compact gathering of Venus, Mars and Saturn, 5.3 degrees wide, on morning of March 28.
Venus passes within 2.2 degrees south of Saturn on March 28 and 29. On the latter date, the 9 percent crescent moon appears within 15 degrees to the lower left of Venus.
On March 30, it will require a very clear sky 20 minutes before sunrise, with an unobstructed view, to spot the 4 percent old crescent moon, just risen, 12 degrees south of east, as well as Jupiter, within 5 degrees to its upper left.
On March 31, the moon can’t be seen—but three planets, Venus, Saturn and Mars, still fit within 6 degrees. Saturn will be the middle one, about 3 degrees from Mars and 3.2 degrees from Venus. The best viewing time may be about one hour before sunup. As the sky brightens, watch for Jupiter rising within 27 degrees to the lower left of Venus. Four planets, Mars-Saturn-Venus-Jupiter, span 32 degrees.
Mars and Saturn will form a close pair 0.4 degrees apart, some 7.5 degrees to the upper right of Venus, on April 5. It’s expected they’ll be closely matched in brightness. Can you notice any difference in their colors? This will be the morning of the least span of the four planets, Jupiter through Venus to the Mars-Saturn pair—30 degrees.
In March 2022, the evening sky, though without a naked-eye planet, still offers plenty of attractions for the unaided eye and binoculars. Orion is well up in the south at dusk, and begins his slide toward the west. Orion is easily recognized by his three-star belt, with bright, blue-white Rigel, his foot, below, and reddish Betelgeuse, his shoulder, above. Below the belt is a short vertical line of stars, Orion’s sword. Through binoculars, the middle of the sword appears as a group of stars in a fuzzy cloud of gas and dust—the Great Nebula, where stars are being formed.
Locate the brightest star, Sirius, not shown on the chart, by extending Orion’s belt to the lower left. The “Dog Star” Sirius completes the nearly equilateral Winter Triangle, with Betelgeuse and Procyon. Extend Orion’s belt away from Sirius to find Aldebaran, eye of Taurus, the Bull. Fainter stars of the Hyades cluster nearby complete the V-shaped head of Taurus. Each arm of the “V” is 4 degrees long, fitting nicely into the field of binoculars. Next, look 14 degrees west of Aldebaran for the beautiful Pleiades star cluster. Both clusters are wonderful sights for binoculars!
Follow the moon at dusk, from a thin crescent low in west on March 2, until full, low in the east on March 17. On March 6 at nightfall, about 1.4 hours after sunset, using binoculars, find a pair of sixth-magnitude “stars,” 0.9 degrees apart, and 2-3 degrees to upper right of the 20 percent crescent moon. The upper left member of the pair is actually the planet Uranus. A telescope magnifying 100-power or more will reveal the difference: Uranus shows a tiny disk, and the star does not.
The evening scene for March 8-13 shows the moon moving through Taurus March 8-10, starting between the Pleiades and Aldebaran on March 8, to near Beta and Zeta, the tips of the horns, on March 10. On March 12, the waxing gibbous moon appears near Pollux and Castor, the bright stars of Gemini, the Twins. On March 15, the moon passes a few degrees north of Regulus, heart of Leo, the Lion, in the eastern sky. Regulus, not shown on the chart, is 37 degrees east of Procyon and Pollux.
Full moon occurs on the night of March 17 (technically, at 18 minutes after midnight on the morning of March 18). Moonrise on March 17 occurs about 21 minutes before sunset, and on March 18 in twilight, about 41 minutes after sunset. For the next few nights, moonrise occurs about 65 to 70 minutes later each night. Instead of staying up late, you can easily follow the waning moon in the morning sky March 18-29.
Spring begins on Sunday, March 20, at 8:33 a.m.
Illustrations of the events in this article can be found in the Abrams Planetarium’s monthly Sky Calendar. To subscribe for $12 per year or to view a sample copy, visit www.abramsplanetarium.org/skycalendar.
Robert Victor originated the Abrams Planetarium monthly Sky Calendar in October 1968, and still produces issues occasionally, including April 2022. He enjoys being outdoors sharing the wonders of the night sky, and is hoping for the pandemic to end! Robert Miller, who provided the twilight charts, did graduate work in Planetarium Science and later astronomy and computer science at Michigan State University and remains active in research and public outreach in astronomy.