February Sky Chart; Northern Hemisphere gazer's guide

Feb. 1: Saturn, rising in the late evening, begins its retrograde (westerly) motion. Watch it move to the right toward Spica during the next three weeks. Saturn passed Spica going east (to the left) in early January, and it will pass the star going west (to the right) later this month. But it will be back again in September to pass Spica for the third time this year.

Feb. 1: First quarter moon.

Feb. 2-3: The waxing gibbous moon is in Taurus, passing beneath the Pleiades (Seven Sisters) on the 2nd. The bright reddish star above the moon is Aldebaran.

Feb. 5: The two stars in line above the moon are Pollux (the lower) and Castor (the brighter) in Gemini.

Feb. 5: The moon is at perigee, the position in its orbit nearest to Earth.

Feb. 8: Full moon.

Feb. 10: Venus, stationary among the stars, resumes its direct (easterly) motion, slowing the rate at which it separates to the sun's right. In the morning sky, quite bright, it rises in the east at dawn, but remains low through twilight.

Feb. 12-13: Be sure to look for Mars, Saturn, and Jupiter on these nights, when the moon serves as a bright pointer for them. On the night of the 12th from moonrise (about 10 p.m.) on you will see Mars, Saturn, and Spica just below the moon, and Jupiter to their east (left). If you watch for a half hour or so, you should easily observe the moon slide slowly above them from right to left. Look again on the 13th after moonrise (about 11 p.m.) and the moon will be above Jupiter (the brightest of the planets), with ruddy Mars (second brightest) well to the right, Saturn and Spica (the bright star of Virgo) in between.

Feb. 12: Mercury (also in the morning sky, but not so you'd notice it!) is stationary, ending its retrograde (westerly) motion.

Feb. 15: The last quarter moon is near Antares, in Scorpio.

Feb. 17: The moon is at apogee, farthest from Earth.

Feb. 20: The morning sky is full of easily seen planets! The waning crescent moon points upward to Venus, the brightest starlike object visible, low in the east at dawn. Place the moon and Venus on your left, and over on your right, still high above the horizon, are Jupiter (highest), Saturn and Spica (lower and much dimmer), and Mars (lowest and second brightest).

Feb. 21: Now it's the turn of Mars to reverse direction among the stars. Coming up to its opposition from the sun in late March, the planet begins to move westerly (retrograde), taking it away from Spica and Saturn (it moves westward faster than Saturn). At this point in its cycle of configurations relative to Earth, Mars brightens and becomes prominent in the night sky very rapidly. Watch for the next eight weeks or so for some surprises.

Feb. 23: New moon.

Feb. 24: It's Jupiter's turn to begin its retrograde swing. All three of the bright planets near Spica (Jupiter, Saturn, and Mars) are now moving to the right relative to Spica and the other stars. Watch them to see which moves most rapidly, which more slowly.

Feb. 24: Venus, the lonely planet over in the morning twilight (but easily the brightest), reaches greatest brilliancy in the dawn sky. Increasing distance between Venus and Earth now begins to dim the planet, overcoming the effect of its waxing in phase.

Feb. 25: Saturn, moving retrograde, makes its second pass by Spica this year. No. 1 of the triple conjunction was on Jan. 8; No. 3 comes up in September.

Feb. 26: The waxing crescent moon of the new cycle should be visible in the evening twilight tonight, should certainly be (weather permitting) tomorrow night.

All month: The names ''evening'' or ''morning'' star depend on whether the planet is above the horizon at sunset (evening star) or sunrise (morning star). It can't be both. And it has nothing to do with whether we can see the planet or not.

This month, when Mercury moves west of the sun, all the planets are morning stars; all are above the horizon at sunrise. We will not see Mercury. Venus will be visible low in the southeast at dawn if the horizon is clear (because Venus is so bright). Mars, Jupiter, and Saturn rise well before midnight and will be a striking trio from late evening (rising in the east) until dawn (setting in the southwest). And, of course, Uranus, Neptune, and Pluto are too dim to be seen. Is it exceptional for all the planets to be morning stars all month? Yes! It doesn't happen very often. But it has no real significance, except as it affects the appearance of the sky for those interested in watching it.

But the morning stars this month do produce an exceptional morning sky scenario, at least from midmonth on. Venus is exceptionally bright low in the east at dawn and makes a beautiful pair with the crescent moon on the 20th. Mars , Saturn, Jupiter, and the nearby star Spica are worth watching all month long, in the west at dawn, but rising in the east in the late evening.