As its namesake month begins, Mars glimmers below brilliant Venus in the predawn sky. To the right (south) of the planets sits the Teapot of Sagittarius, while the curved Teaspoon of stars hangs above and between the Teapot and the planets. Moving south again, look for the sinuous form of Scorpius and its red heart, Antares.
Mars inches upward all month long, and Saturn climbs over the horizon in mid-month. The ringed planet passes below Venus between March 27 and 28, and ends March below and between its two fellow planets. A waning moon visits Antares on March 23, then sails toward the planets. On March 28, a scrawny old crescent moon rises below the three planets. But to see all four objects, you’ll have to look soon after moonrise, or the sun will have washed out at least some of the planets.
In the evening sky, the large knot of bright winter constellations makes its last stand in March. If you haven’t seen them, look to the south to southwest at nightfall. Enjoy Sirius, in Canis Major, the big dog, at the bottom of the group, then look up to brilliant Capella, at the top in Auriga, the charioteer. The starry assemblage is so tall, you’ll have to lean your head back to see Capella.
March’s full moon shines the night of March 17 and 18 from below the tail of Leo, the lion. As the night goes on, the moon and the lion seem to drive the winter constellations westward.
The spring equinox arrives at 10:33 am on March 20. At that moment, the sun crosses the equator into the northern sky and an observer in space would see Earth lighted from pole to pole. Also, the spring equinox ushers in six months during which the day length increases as we travel north. And even if we stay put, we experience the fastest increases in day length near this equinox because it’s the time of year when the sun moves most rapidly northward.
March 2—New Moon
The Moon is located on the same side of the Earth as the Sun and is not visible in the night sky. This is the best time of the month to observe faint objects like galaxies and star clusters because there is no moonlight to interfere.
March 10—First Quarter Moon
The Moon is one-quarter of its way through its orbit around the Earth, which makes half the Moon illuminated and half dark from our perspective. This is the best time of the month to see the Moon’s surface features like craters and mountains through binoculars or a telescope.
March 18—Full Moon
The Moon is located on the opposite side of the Earth as the Sun and the side we see is fully illuminated.
March 25—Third Quarter Moon
This phase occurs when the Moon is three-quarters of the way through its orbit around the Earth.