Astronomy news for the week starting Friday, April 20, 2001.

The Moon passes through its new phase this week on Monday the 23rd. As the waning crescent thins, it passes ten degrees south of Venus around mid-day on Friday the 20th, and on the morning of Saturday the 21st will be well below the bright planet, which now lights up the eastern dawn sky. After passing the Sun, the waxing lunar crescent will be barely visible in western twilight the evening of Tuesday the 24th. The following night, Wednesday the 25th, the crescent, glowing softly with earthlight, will make a fine four- part configuration with Saturn, Jupiter, and Taurus's bright star Aldebaran, the Moon positioned about halfway between the two planets. By the evening of Thursday, the 26th, the Moon will appear well up and to the left of Jupiter, having passed south of it during the day (for those in the Americas).

The two bright evening planets will not be with us too much longer, as Saturn now sets around 9 PM (daylight time), Jupiter an hour later. Mars, however, takes over, the red planet now rising around midnight between the classical figures of Scorpius and Sagittarius. Mercury is completely out of sight, as it passes in back of the Sun in superior conjunction on Monday, the 23rd.

The minor bodies of the Solar System weigh in this week in the form of the Lyrid meteor shower, which peaks the morning of Sunday the 22nd. The Lyrids, which appear to emanate from the constellation Lyra, are the rocky debris of Comet Thatcher (1861 I), whose orbit we are passing. It is usually a modest shower, producing perhaps 10 meteors per hour, but is capable of up to 100.

The summer stars, represented here by Lyra, are yet to come however. Now it is time to admire those of spring. Just after the end of twilight look high to the south to find the great figure of Leo, the Lion, this zodiacal constellation looking for all the world like a great beast stalking the sky, his head outlined by the "Sickle," which ends in Regulus. His hindquarters are marked by a prominent triangle whose eastern star is Denebola. Then follow the curve of the handle of the Big Dipper (nearly overhead for most in North America) to find Arcturus in Bootes and then Spica in the Zodiac's Virgo, this lonely star seen to the left of the box that makes Corvus the Crow. Almost exactly between Regulus and Spica lies the autumnal equinox, the point where the Sun crosses the celestial equator to mark the beginning of fall (which this year will happen on September 22). Since the Sun has recently passed the Vernal Equinox in Pisces, its opposite is nicely "visible" (in our imaginations) at night. Down and to the right of Leo is Alphard in Hydra, the water serpent, and just up and to the left of Alphard is the modern constellation Sextans, which honors the venerable sextant, the prime tool of the celestial navigator.
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