Northern Hemisphere gazer's guide
March 1: The star to the left of the 5-day old waxing crescent moon is Aldebaran, in Taurus.
March 2: Aldebaran is to the right of the first quarter moon.
March 4: The moon is at perigee, the point in its elliptical orbit nearest to the earth.
March 5: The two stars above the gibbous moon are Pollux and Castor, the ''Twin'' stars of Gemini.
March 7-8: The moon passes Regulus, in Leo. The moon moves from the star's right (west) on the 7th to its left (east) on the 8th.
March 9: The full moon is south of Denebola, in Leo.
March 10: Mars, Saturn, and Jupiter stretch out in line to the moon's left (east). The star beneath Saturn is Spica, in Virgo.
March 11: The gibbous moon is between Mars (to its right) and Saturn (to its left). Spica is also left of the moon, below Saturn, and Jupiter is well to the left of both.
March 12: The exceptionally bright object to the moon's left is Jupiter, with Saturn, Spica and Mars farther away to the right. Watch the moon carefully for a half-hour or so and you can easily see its motion to the east (left) relative to the bright, nearby planets.
March 13: The moon trails behind Jupiter tonight as the planets parade up the eastern sky a few hours after sunset.
March 17: The last quarter moon is at apogee, farthest from earth. It is located in Sagittarius, just above the ''Teapot,'' rising an hour after midnight.
March 17: Although the sun doesn't reach the vernal equinox for several more days, this is the date on which there are 12 hours of day and 12 hours of night. The sun doesn't actually cross above the equator until the 20th, but the duration of daylight is increased by the refraction of sunlight in passing through the earth's atmosphere, and by the fact that we measure sunrise and sunset from the upper edge of the sun.
March 20: The sun arrives at the vernal equinox today at 5:56 p.m., Eastern standard time, and spring begins in the Northern Hemisphere. The vernal equinox is the point on the sky where the plane of the earth's orbit and the plane of the earth's equator intersect. There are two such points, of course, but the one at which the sun is located in going from south to north of the equatorial plane is the vernal (spring) equinox. The other is the autumnal equinox. It isn't a ''fixed'' point relative to the stars, however. It moves west slowly as the equatorial plane shifts around because of the effects of precession on the earth's axis of rotation. Confusing? Maybe, but this is the reason why the year of our calendar is some 20 seconds shorter than the period of the earth's revolution around the sun.
March 21: The waning crescent moon and Venus make a pretty pair in the dawn sky this morning.
March 25: New moon. Expect to see the slim young crescent in the evening sky on the 27th or 28th.
March 29: The moon is at perigee again, second time this month.
March 31: Mars is at opposition from the sun, rising at sundown, setting at sunrise. It now becomes an evening star. You may have noticed how much it has brightened this month, more than double. Well, it will be dimming in April just as rapidly.
All Month: Except on the last day of the month, when Mars is in opposition from the sun, all of the planets are morning stars in March. Mars, Jupiter, and Saturn are well placed for most of the night all month; Venus, though not at its best, should be very easy to find because of its brightness, low in the east as dawn breaks; Mercury, though going through a long and well-separated (from the sun) morning elongation, rises too late and stays too low to be seen.
Don't fail to look for Mars, Jupiter, and Saturn, however, putting on a show even better than last summer and fall. A few hours after dark each evening, they are stretched out in line from the eastern horizon upward, with Spica among them. Mars rises first soon after dark, Saturn and Spica within an hour, and Jupiter about two hours later. During the night they swing upward to the right, and then curve down again toward the west as dawn approaches.
No matter when or where you see them during the night, the brightest is Jupiter, Mars is next, and Spica (below) and Saturn (above) a poor third in between the two brighter planets. Mars is putting on one of its classical opposition shows, brightening very rapidly this month, then dimming just as rapidly in April, as it closes swiftly with earth and then just as swiftly separates.
Exaggerated rumors about a close alignment of planets in 1982 and its possible effects have been circulated for years. It is not uncommon for all the planets to be on the same side of the sun, but there is no reason to believe it would have noticeable effects on the earth. The closest gathering of planets in the 1980s occurs this month on the 10th, when they will all be located within an arc of about 98 degrees, measured from the sun. We don't see anything better than this for the rest of the 20th century.
