Northern Hemisphere gazer's guide

The sky chart is designed to correspond to the sky at 10 p.m. the first of the month, 9 p.m. in the middle of the month, and 8 p.m. at the end of the month standard time. All month: Venus leaves the morning sky in February; Jupiter enters it; Saturn and Mars remain morning stars; and Mercury gives us our best shot at seeing it in a long while during the last week of the month.

All that switching around doesn't really improve our sky picture materially, however. Venus will be obscure for another two months, and Jupiter will not recover in the morning until the end of March. Saturn and Mars offer the most planetary excitement of February. Mars moves past Saturn (right to left) and brightens as its July opposition from the sun approaches. From January to February the planet brightens by a full magnitude, more than double.

A clear and unobstructed western horizon will be necessary to see Mercury, but with these advantages the planet can be found during the last week of the month. Its brightness compares with that of the stars (Sirius and Canopus), and it will be high enough at sundown to pick out before it sets.

(Events in the calendar below are given in local time unless otherwise indicated.)

Feb. 1: Last night the moon rose just before midnight; tonight just after. Last quarter phase occurs at 11:41 p.m. Eastern standard time (EST), but we won't see the moon until it rises in the wee hours of the morning on the second, in Libra.

Feb. 3-4: The moon repeats its performance of January with Saturn and Mars. It passes above both on the 3rd only 13 hours apart. Moonrise is after 2 a.m. From about 4 a.m. on (when the moon is high enough), look close-by for the two planets, Mars nearer. The reddish star nearby is Antares, in Scorpius.

Feb 4: Perigee moon (nearest earth) occurs today.

Feb. 5-6: The waning crescent moon is low in the southwest, and difficult, but not impossible, to see. Next chance will be after the new moon.

Feb. 9: Comet halley reaches perihelion (nearest the sun), 54 million miles distant. This last occurred on April 20, 1910.

Feb. 9: New moon is at 7:55 p.m. EST, just before the moon leaves Capricornus to enter Aquarius.

Feb. 10: Saturn changes its stellar position very slowly. It has taken it a long time to pass Antares, the brightest star of Scorpius, near it this morning. It won't pass the star again for another 30 years. Don't confuse the star with Mars, close-by to the right of Saturn. Both Antares and Mars are similar in brightness.

Feb. 11: Our first chance to see the young crescent moon in the evening will be tonight, just as it passes below the vernal equinox. The crescent will be higher, brighter, and set later tomorrow night.

Feb. 14: Aries's stars can be seen above the moon tonight, Hamal (the brighter) and Sheratan.

Feb. 16: First-quarter moon (at 2:55 p.m.) nearly coincides with apogee moon (about 5 p.m. EST). The Pleiades (the tight star cluster also known as the Seven Sisters) are just above the moon.

Feb. 17: Aldebaran, the reddish star of Taurus, is below the moon as it comes up.

Feb. 17-18: Mars caught Saturn during the night, moving from right to left below it. The two planets will appear nearest one another on Tuesday morning, separating slowly thereafter. Jupiter is in conjunction with the sun on the 18th, ending its sojourn as an evening star.

Feb. 19-20: Gemini is home to the moon, near the ``twin'' stars Pollux and Castor on Thursday evening.

Feb. 21-22: Trace the moon's motion in orbit these nights as it moves through the dim stars of Cancer, away from Pollux and Castor, toward Leo's Regulus.

Feb. 24: Full moon is at 10:02 a.m. EST, still in Leo.

Feb. 25-28: The moon moves through Virgo, waning through its gibbous phase. The star below it on the 27th is Spica, a good beacon by which to note the moon's easterly drift through the stars.

Feb 28: Mercury's greatest elongation offers the best opportunity to see the planet. Evening elongations are always better in late winter, and the planet is always brighter during an evening appearance before greatest distance from the sun occurs. With a clear westerly horizon, you could see the planet during the last week of February, low in the west during late twilight.