STAR TRAK for March 2012
Mars was opposite the sun in our sky on March 3, rising at sunset and remaining visible all night. If you looked to the east as the sky darkened, you could see the Red Planet gleaming at its biggest and brightest, which happens only once every two years. The best views through a telescope are when the planet is highest in the south around midnight. Mars glows red-orange in the constellation Leo the Lion, with the bright white star Regulus nearby to the upper right (west).
Venus and Jupiter will make a spectacular pair in the western sky all month, from sunset until mid-evening. Venus will reach its greatest separation from the sun on March 27, standing high in the west-southwest after darkness falls. This will be Venus' highest appearance in its entire eight-year cycle. By March 31, the planet will be 3 degrees below the bright Pleiades star cluster in the constellation Taurus the Bull.
At the beginning of the month, gleaming white Jupiter was about 9 degrees to the upper left (east) of Venus. The gap between the two planets will narrow until, between March 12 and 15, they will be 3 degrees apart. Venus will pass north of Jupiter before dawn on March 15. During this period the pair will be a third of the way up the western sky an hour after sunset, not setting until almost four hours after the sun. The best views of this conjunction will be with the unaided eye or through binoculars, but each planet will be a good target for viewing with a telescope during March.
At the beginning of the month, Saturn rose about four hours after sunset to glow bright yellow in the southeast among the stars of the constellation Virgo the Maiden. By month's end it will rise three hours earlier. The tilt of its rings to our line of sight will narrow slightly during March. The best telescopic views will come after midnight when the planet is above most of the turbulence near the horizon.
Saturn has more than 60 moons, and the largest one, the planet-sized Titan, can be seen with any telescope. It completes two orbits around the planet each month. Titan will be due south of Saturn on the night of March 18, and due north on March 10 and 26. Visit saturn.jpl.nasa.gov for the latest news and images from the Cassini spacecraft orbiting Saturn.
Mercury will be the lowest of the planets in March. Early in the month it will appear a half hour after sunset near the west-southwestern horizon, far below brilliant Venus. It will fade rapidly after that, and by March 13 it will be too faint to see in bright twilight. Mercury will pass between Earth and the sun on March 21.
The sun will cross the celestial equator (an extension of Earth's equator onto the sky) on March 20 at 1:14 a.m. EDT (5:14 Universal Time) heading north. This will mark the start of spring in the Northern Hemisphere and fall in the Southern Hemisphere. For the next six months in the Northern Hemisphere, the days will be longer than the nights.
Day and night are not precisely the same length at the time of the equinox. That happens on different dates for different latitudes. At higher latitudes in the Northern Hemisphere, the date of equal day and night occurs before the March equinox. In the Southern Hemisphere, this happens after the March equinox. Information about the exact time of the equinox at different places on Earth's surface is provided at aa.usno.navy.mil/faq/docs/equinoxes.php .
An event called the Globe at Night star count, now in its seventh year, has drawn thousands of participants worldwide (projectdarkskies.org). The purpose is to get the public excited about what can be seen in the night sky, but to emphasize that many of these celestial sights are being lost to light pollution.
The moon will be full on March 8, at third quarter on March 14, new on March 22 and at first quarter on March 30.