| The Magazine of the CALIFORNIA ACADEMY OF SCIENCES |
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Skyguide January to March 2001 January 9 Full Moon in Gemini. A total lunar eclipse occurs as the Full Moon passes through the Earth's dark, reddish shadow. This happens during daylight hours for North America, when the Full Moon is below the horizon, so it's visible only from Europe, Asia, and Africa. January 24 New Moon at 5:07 a.m., pst-only about twelve hours old by sunset tonight and not visible to the naked eye. Try to find it tomorrow (the 25th), low in the west-southwest, very soon after sunset. Don't forget on the 25th to also use that opportunity to look for the elusive planet Mercury, just above the Moon. February 7 Tonight's Full Moon rises at sunset on the edge of the constellation Cancer and enters the stars of Leo during the night. The brightest star near the Moon is Regulus, which represents the Lion's heart. February 23 New Moon at 12:22 a.m. When the Sun sets at 5:57 p.m., a razor-thin, 17-hour-old waxing crescent will be located low in the west––Wow! Binoculars may help to see it. March 9 Full Moon entering the stars of Virgo, near the star Denebola, which marks the tip of the tail of Leo. March 20 Spring Equinox for the Northern Hemisphere (Fall Equinox for the Southern Hemisphere) at 5:32 a.m., pst––often called simply the March Equinox. The Sun rises due east, sets due west, and spends essentially the same amount of time above the horizon as below. March 24 New Moon at 5:22 p.m. Not visible tonight-look for a thin crescent low in the west after sunset tomorrow (the 25th). The Planets Mercury This little planet starts off in the evening sky, then leaps into the morning twilight. Greatest eastern elongation (18 degrees east of the Sun and setting in the evening) is on January 28, when it will be easy to see, as the angle of the ecliptic is high. An inferior conjunction occurs February 13, after which it becomes a morning object not visible until after about February 20, when it starts climbing out of the morning twilight. Greatest western elongation occurs March 11 (17 degrees west of the Sun and rising before dawn). Skywatcher's challenge: Mercury is in conjunction with Uranus on January 22-can you spot them, both about 15 degrees above the horizon at sunset? Binoculars may be needed to see them, starting about a half-hour after sunset. The Moon passes close by on the evening of January 25, and the mornings of February 21 & March 22. Venus The brightest of the planets opens the year as a prominent evening object high in the southwest after sunset. Greatest eastern elongation is on January 17, after which it starts gradually descending back into the twilight, moving slowly northward with the Sun from one night to the next. A combination of distance and phase results in greatest brilliancy on February 21, when Venus is a magnificent beacon during evening twilight. Inferior conjunction, when Venus is between Earth and the Sun, is on March 30, after which Venus moves into the predawn sky. Mars The Red Planet is a morning object this quarter. In January, look for it high in the south-southeast just before dawn, slowly exiting the constellation Virgo and entering the stars of Libra. By the end of February, it will pass quickly through the left claw of Scorpius, then in early March it moves into Ophiucus the Serpent-bearer, where it remains until nearly the end of April. Note that in early March, Mars passes near the red star Antares. This star marks the heart of Scorpius and is named after Mars because of its similar color ("Antares" = "anti-Ares" = "rival of Mars"). Jupiter Having passed opposition in November, Jupiter will rise more than two hours before sunset and will be prominent in the eastern sky after dark. Located against the stars of Taurus, it forms a pretty triangle with Saturn and the Pleiades star cluster. By mid-February it will be overhead at sunset, and by mid-March, it will have crossed over to the western half of the sky and will be seen slowly descend- ing toward the glow of the setting Sun. The Moon passes nearby on the evenings of January 5 and 6, February 2, March 1, and again on March 29. Saturn Like Jupiter, Saturn passed opposition in November and so is high in the east after sunset in Taurus. Jupiter and Saturn were in conjunction in late May and have been slowly moving apart since then. Because these are the outermost of the naked-eye planets, they're also the slowest-moving, which is why it seems to be taking so long for them to separate from one another. Through a small telescope, Saturn's spectacular rings are easily visible. The Moon sweeps by on January 5, February 1, and March 1.
Times are for San Francisco, CA, and are accurate to within two minutes. B.F. Quock, Morrison Planetarium, bquock@calacademy.org
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