At that time, the center of the Sun's disc crosses the celestial equator and passes into the northern hemisphere of the sky. It marked the traditional start of a new year in many cultures as far back as Roman times, and today it sets the dates for important feasts and fasts in many religions.
The point in the sky that defines the equinox is sometimes referred to as the “first point of Aries,” a term still widely used in astrology. In Babylonian times, when the basic principles of astrological practice were established, the constellation of Aries, Rama, was the seat of the equinox.
Today, the equinox is actually about 30 degrees to the west in the constellation of Pisces, thanks to a 26,000-year cycle known as the “precursor of solstice.” In 3,000 years, the equinox will be between the stars of Aquarius; It will return to Aries somewhere around the year 23,000.
The word “equinox” refers to the concept of “equal night”, when day and night are exactly 12 hours long. In fact, the upper limb of the Sun rises above the horizon a few days before the equinox. The actual date for 12 hours of daylight and darkness in DC this year is March 16, with Old Soul rising at 7:17 a.m. ET and setting at 7:17 p.m.
Moon notes, set that alarm
As March begins, you will see the waning moon adorning the morning sky. On the morning of the 3rd, early risers can catch the last quarter moon at dawn in the southern part of the sky. Less than a degree away is the bright red star Antares, the heart of Scorpius, Scorpion.
The new moon comes on the 10th. Luna waxes in the evening sky and reaches full phase on the 25th. The traditional name for the March full moon is the worm moon, because the ground is soft enough for earthworms to find the surface, providing a food source for birds and animals. Other traditional names are crow moon and chap moon.
If you want to go to any engagement on Sunday morning, you should set your clock an hour before going to bed on Saturday night. Unless you live in Arizona or Hawaii, US code dictates that we all switch from standard to daylight saving time at 2 a.m. on March 10th. During my years at the US Naval Observatory, I have fielded hundreds of questions about why this happens every year. But implementation is not ours.
In the United States, civil time is governed by congressional authority through the Department of Transportation. The laboratory maintains a single reference time scale called UTC. We leave it to others to decide what to do with it.
From the Big Dipper to Arcturus
By mid-evening you can see the winter constellations that helped us through the long winter nights in the western sky. At the end of the month, they will be set at midnight. If you enjoy looking at Orion and its bright star companions, this is the last month to get a good view until late fall.
After March, the more subdued constellations rise at night. The most recognizable pattern among them is the group of stars known to most of us as the Big Dipper.
These seven stars form a distinctive pattern that outlines a venerable soup ladle, and is usually one of the first stars new astrologers learn to identify. It is called a plow (plough) in Britain and Ireland, and a vain (wagon) in other parts of Europe. The seven stars are part of the great constellation of Ursa Major, the Great Bear. The two stars at the end of the Dipper's “bowl” point north to the star Polaris, which represents the north celestial pole.
Follow the “pointers” south and you'll encounter the constellation Leo, the Lion, with two distinct star groups. Regulus, Leo's brightest star, sits below the semicircle of second-magnitude stars that outline the lion's head. To the east of Regulus, you can see a right-angled triangle of stars marking the back of Leo.
As you approach the Big Dipper, follow the curve made by its “handle” and you'll encounter Arcturus, the signature star of spring. It is the brightest star in the northern sky and the fourth brightest overall at its nearest 37 light-year distance and is hard to miss due to its luminosity, which is 170 times that of the Sun. Its rose color is reminiscent of the colorful flowers that bloom from March to April.
March can be a dull month for planet watchers. The only bright member of the Solar System is Jupiter, which dominates the western sky during the evening hours. In early March, the giant planet sets between 11pm and 10:30pm, but after we switch to daylight saving time, you'll have no problem finding Jupiter after sunset.
Once Jupiter sets, there are no bright planets to look for the rest of the night. Just before dawn, you'll be able to see Venus in the gathering twilight, but it'll be very low in the southeastern sky.
However, towards the end of the month, we get a chance to see the most elusive of planets, Mercury. The best time to view Mercury is from March 17 to March 31, 30 to 45 minutes after sunset, when it is about 10 degrees above the western horizon. If you have them, use binoculars to look for them in the twilight. Once you find it, you can spot it with the naked eye.
Sky views in the DC area in March
The climate is mild. Here are some places to see through binoculars this month.
- George Mason University Lab – Free public lectures and telescope tours every week!
- Every Friday (weather permitting) – Visit Observatory of the Analemma Society at Turner Farm Park in Great Falls, Va.
- March 2 and 16 – Greenbelt Star Party Nights Astronomical Society of Greenbelt.
- March 9 – Public Watch Night Northern Virginia Astronomical ClubCM Crockett Park in Midland, Va.
- March 9 – Stargazing Steven F. Yard-Hazy Center Chantillyam, Va.
- March 16 – “Astronomy for All.” Come see the stars Northern Virginia's only international dark ski park!
For a list of astronomy clubs, planetariums, science centers, and observatories in the metro DC, Baltimore, and Richmond areas, see This website is from the US Naval Observatory.
