Sunrise and Sunset Times for March 2010

DAYLENGTH
Daylight Savings Time begins Sunday, March 14, when clock time jumps from 2:00am to 3:00am. In addition to an extra hour of evening light contributed by the change in clock time, the period of daylight increases substantially in March. Sunrise occurs 45 minutes earlier by month’s end and sunset 30 minutes later, adding up to 75 minutes more of daylight. Twilight also extends the daylight period. Civil twilight provides about one-half hour of strong light after sunset. Nautical twilight continues another half hour as color and detail disappear from the landscape. Astronomical twilight fades to darkness about one and one-half hours after sunset. (The time of sunrise and sunset assumes a flat horizon. Actual time may vary depending upon the landscape.)

MOON HAPPENINGS
March begins with a waning full moon from February 28. It rises after 8:00pm below Saturn. March 2 it rises more than an hour later near Spica (Virgo). By March 5 the moon rises after midnight. The last quarter moon occurs March 7. A new moon occurs March 15. Within the next few days a waxing crescent moon appears in the evening sky above Venus. March 20 the crescent moon appears to move one-half degree per hour from west to east across the Pleiades. Since the east side of the moon is in shadow, it occults the visible stars in its path. The first quarter moon occurs March 23. March 24 a waxing gibbous moon appears high in the evening sky near Mars. March 28 a nearly full moon rises in the evening sky below Saturn. A full moon rises March 30 at 8:53pm with Spica (Virgo) again in the background. (The time of moonrise and moonset assumes a flat horizon. Actual time may vary depending upon the landscape.)

VERNAL EQUINOX
Pause at 11:32am on March 20 and look towards (not at) the sun. At that moment the sun will be directly over the equator marking the beginning of spring. In astronomical terms, the ecliptic (sun’s apparent path across the sky) intersects the celestial equator (imaginary line across the heavens directly above the earth’s equator). The ecliptic traces the sun’s path across the sky throughout the year. It is identified by the constellations of the zodiac. At the summer solstice, the sun is as far north as the lower end of Gemini (23.5 degrees N). On the winter solstice it is farther south than Sirius in Canis Major (23.5 degrees S). From any location on earth, the sun will appear within this band of the ecliptic (23.5 degrees north or south of the equator). The ecliptic marks the plane of the earth’s orbit around the sun. Most of the planets and Earth’s moon are found within the band of the ecliptic because the planes of their orbits are approximately the same as the plane of the earth’s orbit. To identify the celestial equator, look for the three stars of Orion’s belt. The celestial equator runs along these three stars through Virgo to the east and through the middle of the summer constellation Aquila..

LOCAL STAR COUNT
Gather at Old City Park on Saturday, March 13, for a tour of the night sky and the Globe At Night Star Count. Red Rock Astronomers will provide telescope viewing. Meet at 6:45pm in the lower field beyond the bandstand. Dress warmly and bring a chair or blanket and a flashlight. All ages are welcome. Call 259-4743 or 259-3313 for more information. Sponsored by WabiSabi.

ZODIACAL LIGHT
Imagine sunlight streaming through a window and illuminating dust particles floating in the room. In the same way, the setting sun illuminates dust particles present in the inner solar system. Near the vernal equinox, the sun’s rays shoot high into the sky at sunrise and sunset, and we can see this display. It is the zodiacal light. Best time to view at night is the first week of March before the moon brightens the sky. Find a high vantage point with a clear view of the western horizon. As astronomical twilight fades, look for a cone or beam of light originating from the point where the sun set and leaning a little to the south. March 23-April 6 the zodiacal light is visible on the eastern horizon before astronomical twilight brightens the morning sky.s

Note: Hold your hand at arm’s length to measure apparent distances in the sky. Adjust for the size of your hand. The width of the little finger approximates 1.5 degrees. Middle, ring, and little finger touching represent about 5 degrees. The width of a fist is about 10 degrees. The hand stretched from thumb to little finger equals 20 degrees. The diameter of both the full moon and the sun spans only 0.5 degree.

VISIBLE PLANETS
Mars - Face SSE and look high in the sky. The bright red-orange disk in the dim region of sky between Leo and Gemini is Mars. It outshines both Castor and Pollux (twin stars of Gemini). Mars ends its retrograde motion March 11 and resumes its eastward drift back through Cancer. By month’s end it will be 5 degrees west of the Beehive Cluster (Praesepe). Mars continues to lose magnitude and size this month as it recedes from Earth. (Magnitude 0)

Saturn - Look due east in the evening twilight for Saturn’s golden orb to rise on the celestial equator. It follows Leo into the sky and appears in the faint eastern region of Virgo. By midnight Spica (Virgo) will rise a little farther south and form a line to the west with Saturn, Regulus (Leo), and Mars. Its retrograde motion makes it appear to move westward through Virgo. Saturn reaches opposition (opposite side of the Earth from sun) March 21. It rises with evening twilight, appears overhead around midnight, and sets with the morning twilight throughout the month. (Magnitude +0.5)

Venus - Find a high vantage point and a clear view of the western horizon to see Venus this month. Look for it in early evening twilight. March 29-31offers a chance to see Mercury. Use binoculars to scan the sky between Venus and the horizon for Mercury’s dim apparition. Venus is in Pisces this month, but the constellation will be too faint to be visible in evening twilight. (Magnitude -4)

Note: Apparent magnitude values range from -4 to +6 for most planets and visible stars. The lower the value the brighter the object. A decrease of 1.0 magnitude is 2.5 times brighter.

Primary Sources: USGS, U.S. Naval Observatory, http://www.fourmilab.ch/yoursky/

MAJOR CONSTELLATIONS this MONTH Overhead Cancer Canis Minor Geminis Northward Cassiopeia Cepheus Perseus Ursa Major Ursa Minor Eastward Bootes Corona Borealis Leo Virgo Southward Canis Major Corvus Hydra Westward Auriga Orion Taurus Winter’s jazzy lights give way to a faint spring sky punctuated with beacons of brilliant light. Sirius and Procyon (dog stars) form a line with Mars from SW to NE. Regulus (Leo) shines overhead. Saturn and Spica (Virgo) accent the southeast. Arcturus (Bootes) pierces the eastern sky before midnight. Hold the star chart high above your head and match the compass directions to the direction you are facing. Adjust the star chart by orienting Ursa Major (Big Dipper) to match its position in the sky. The star chart approximates the night sky from astronomical twilight to midnight. As the night and the month progress, the constellations will shift toward the northwest.