SKYLIGHTS

Astronomy news for the week starting Friday, February 23, 2001.

We begin the week with the new Moon passing beneath a Sun now moving through Aquarius on its way to Pisces and spring. By the evening of Saturday the 24th, the Moon will be visible as a slim crescent in evening western twilight, and will thence grow toward first quarter, that phase to be reached next Friday, March 2.

The evening of Monday, the 26th, the Moon will appear well to the south -- to the left -- of brilliant Venus. The passing angle between Venus and the Moon is unusually large, 11 degrees. The orbits of all the bodies of the Solar system are somewhat tilted relative to Earth's, the Moon's by 5.2 degrees, Venus's by 3.4 degrees. Though the planets and Moon are all found close to the ecliptic -- the apparent path of the Sun -- they therefore still wander noticeably away from it. During this week, the Moon is well south of the ecliptic, while Venus is on the north side, the effect exaggerated by its proximity to Earth as it prepares to head toward conjunction with the Sun. The champion wanderer, of course, is highly-tilted dim Pluto, which now lies 10 degrees north of the ecliptic in the constellation Ophiuchus.

The night of Thursday, March 1, the Moon will be positioned between and below Saturn and Jupiter in Taurus, passing beneath Jupiter after moonset in North America. Both planets are now moving in direct motion to the east and pulling ever-farther apart. Saturn is noticeably on the south side of the ecliptic, while Jupiter lies very close to it.

The winter stars are now in full force, Orion and its companions to the south in mid-evening. Included is the Winter Triangle of Betelgeuse (up and to the left of Orion's three-star belt), Sirius (the brightest star of the sky, down and to the left of Betelgeuse), and Procyon (to the left of Betelgeuse). Oddly, Procyon and Sirius, the luminaries of Orion's two hunting dogs, both have faint tiny "white dwarf" companions, dead stars that have shrunk themselves under gravity to the size of the Earth.

If you have had enough of northern winter, then look later in the evening to the east and northeast to see the harbingers of Spring, Leo and the Big Dipper in Ursa Major, climbing the sky, the Dipper standing on its handle. As the Earth swings a degree per day around the Sun, the stars seem to creep a degree per night toward the west. Before long, for those in North America, the Dipper will ride overhead on a warm May night, while people in the southern hemisphere will be admiring a high view of the Southern Cross, which is readily visible only below about 25 degrees north latitude.