SKYLIGHTS

Photo of the Week.. Planet Earth: Mists shroud a magical view of Alaska's rugged and snowy Aleutian Islands.

Astronomy news for the week starting Friday, March 8, 2002.

The Moon moves through its waning crescent phase this week, the new Moon arriving on Wednesday, the 13th. On the same day, the Moon will be at apogee, and as a result the normal coastal "spring tides" that occur at new and full Moons will not be as high as usual. As the Moon approaches new, it plays tag with the outer and innermost planets, passing south of Neptune the morning of Sunday the 10th, Uranus during daylight in the Americas on Monday the 11th, and Mercury the evening of the same day. Just before these nearly invisible events, Mercury gangs with Uranus, the two in conjunction on Friday, the 8th.

The obscure planets tucked away in the morning sky leaves the evening for the bright ones, the "big four", Venus, Mars, Jupiter, and Saturn. Venus is now visible in bright twilight to the west shortly after sunset. For a brief moment it is unmistakable, then sets quickly after the Sun. Watch it climb out of the evening mist during the month. While Venus orbits inside the Earth's solar path, Mars brackets us to the outside. Well above Venus to the west, the red planet remains setting around 10 PM, its northerly trek along the ecliptic balancing the diminishing angular distance between it and the Sun. All alone in Aries, the planet is easy to pick out. Higher yet is Saturn in Taurus still near the Hyades, and higher yet, now crossing the north-south line as twilight ends, is brilliant Jupiter, far north within the confines of Gemini above Orion. Jupiter will reach its most northerly position in its 12-year orbit, 23 degrees 27 minutes north of the equator, on Wednesday, March 13.

Geometric figures abound across the sky. The Great Square of Pegasus is one of the most beloved figures of the celestial sphere, while Spica, Cor Caroli, Arcturus, and Denebola are connected by the lesser-known Great Diamond. The most popular figure, though, is the triangle. Northern Winter is dominated by the Winter Triangle of Betelgeuse, Sirius, and Procyon, while summer's heat is marked by the Summer Triangle of Deneb, Vega, and Altair. Triangles constitute two whole constellations. Far south of the celestial equator lies Triangulum Australe, the Southern Triangle, which is visible only from the Tropic of Cancer and south. Far more famed is the classical ancient figure of Triangulum, which lies to the north of the zodiacal constellation Aries, whose southern portion now holds Mars. So popular is the triangle that the seventeenth-century astronomer Hevelius even created "Triangulum Minor" from three stars to the south of classical Triangulum. The little figure, still there for us to see, died a quiet death not long after and -- like many other figures scattered across the sky -- is no longer formally recognized.