February 2008

by Deane Morrison

Dead of winter? Not this February. The shortest month packs in so many events we hardly have space to talk about them, so let's get to it.

The starting gate is hardly up when Venus and Jupiter sweep by each other in the predawn sky. Look close above the southeastern horizon about an hour before dawn on the 1st, and you'll see brilliant Venus pass just over a full moon's width from Jupiter. After this encounter, the two planets promptly separate, with Venus dropping toward the sunrise and Jupiter continuing what will be a long climb through the morning sky.

On the 2nd we'll wake to the news of whether Punxsatawney Phil saw his shadow or not. Groundhog Day, a survivor from ancient Celtic times, was one of four cross-quarter days falling midway between a solstice and an equinox. Cloudy weather on this day portended well, for clouds meant warmth and rain to loosen up soils for planting. But bright sun was taken to predict cold and low humidity. Thence came our modern tradition that if the groundhog sees its shadow, six more weeks of winter will follow.

There's a good moon on the rise the evening of the 20th, when we in the Northern Hemisphere have a ringside seat for a total lunar eclipse. Called the full snow moon or full hunger moon by Algonquin Indian tribes, the softly glowing orb rises around 5:30 p.m. and first touches the Earth's penumbra, or light outer shadow, at 6:35 p.m. The moon contacts the umbra, or dense inner shadow, at 7:43 p.m. and is completely engulfed by 9:01 p.m. The moon remains totally eclipsed until 9:51 p.m., when it begins its exit from the umbra.

The whole spectacle will be framed by Regulus, the brightest star in Leo, to the west and Saturn, now close to peak luminosity, about four degrees to the east. As the moon dims, these two will stand out more. And if the moon gets dark enough, you may get a good view of the Beehive star cluster west of Regulus, about halfway to the Gemini twins.

Saturn reaches opposition on the 24th, when Earth slips by the giant planet and it appears opposite the sun in the sky. Its brightness flares to magnitude 0.2, equalling the brilliance of Mars this month. Mars, having been left behind by the Earth in December, is fading but still lovely as it inches toward Gemini from the horns of Taurus.

In the last few days of February, the moon won't rise until after midnight, leaving dark skies for most of the evening. An hour or two past sunset, look for the zodiacal light, a faint, broad finger pointing obliquely upward along the sun's path. Around midnight, sharp-eyed observers may find the Gegenschein, or counterglow, as a faint spot of light high in the south, directly opposite the sun's position on the other side of the world. Both of these elusive phenomena result from sunlight reflecting off a vast field of meteoric dust that lies in the plane of the solar system and stretches out far beyond Earth.

This month is prime for viewing Sirius, the brightest star in the night sky. A perennial jewel, Sirius reaches its highest point in the south in the mid-evening hours, anchoring the bright knot of familiar winter constellations and outshining even Mars and Saturn.

February has a 29th day, or leap day, this year, giving 2008 a total of 366 days. Leap days are added every year divisible by four, except century years that are not divisible by 400. Thus, the year 2000 was a leap year but not 1900 and 2100. Leap days are added to keep the year in sync with the seasons. Because years are almost a quarter-day longer than 365 days, not adding leap days would cause the dates of equinoxes and solstices to shift uncomfortably fast over time.