Last modified: Thursday, April 29, 2004
Venus will plunge from the heights during May
BLOOMINGTON, Ind. -- As evening twilight falls during early May, Venus will blaze forth high in the west, dominating everything in sight as it has done for several months. You may be used to the spectacle by now, but this show is about to end with startling speed.
The brilliant white "evening star" has already passed its highest point in the sky, and it will reach maximum brightness on May 2. Then it will plunge back toward the sun during the next few weeks, and by June it will be gone. On June 8, Venus will pass across the face of the sun for the first time in 122 years, an event called the transit of Venus (http://sunearth.gsfc.nasa.gov/eclipse/transit/venus0412.html). At the beginning of May, Venus will set near midnight, but by the end of the month it will set in twilight. This sudden change is the result of Venus coming toward us, then overtaking and passing us in its smaller orbit, which will make Venus seem to approach the sun very quickly in our sky.
Jupiter will appear high in the south at dusk in the constellation Leo the Lion. Leo's brightest star, Regulus, will be nearby on Jupiter's right (west) but much fainter than the giant planet. This is a fine time to view Jupiter with a telescope, and binoculars will show its four largest moons to the left and right of the planet itself.
Saturn and Mars will appear to the upper left (south) of Venus as the evening sky darkens. At the beginning of May, pale orange Mars will be moving away from brilliant white Venus toward yellow Saturn to its left. On May 10, Mars will be about midway between the two brighter planets, and it will gradually close in on Saturn until it passes slightly above it on May 24. By then both Saturn and Mars will be in the constellation Gemini the Twins, with its bright stars Pollux (on the left) and Castor directly above them. This pretty cluster of planets and stars will remain on display for the rest of the month.
Mercury will be very low in the east about 45 minutes before sunrise by the middle of May for viewers in the Northern Hemisphere. It will disappear into the glare of sunrise before month's end as it crosses to the evening sky. Those watching in the Southern Hemisphere will see Mercury much higher in the east as morning twilight brightens.
Two new comets, NEAT and LINEAR, will be visible during May, though it is not yet clear how bright they will become. Binoculars may be needed to find them. The comets are named for the automated sky-survey programs that discovered them: Near-Earth Asteroid Tracking (NEAT) and Lincoln Laboratory Near Earth Asteroid Research (LINEAR). More information about these comets is available at http://skyandtelescope.com/observing/objects/comets/article_1229_1.asp.
Another new comet, Bradfield, became visible in late April just above the eastern horizon during morning twilight. It may not be visible much longer, however. Information about Comet Bradfield is available at http://skyandtelescope.com/observing/objects/comets/article_1238_1.asp.
A total eclipse of the moon on the evening of May 4-5 will be the top attention-getter of the month, even for those who don't normally watch the night sky. The event will not be visible in North America, but observers in much of South America, Europe, Africa and Asia will see the full moon's color change from bright silver to dull copper as it passes through Earth's shadow. For details about where and when the eclipse will be visible, see http://skyandtelescope.com/observing/objects/eclipses/article_1219_1.asp or http://sunearth.gsfc.nasa.gov/eclipse/OH/OH2004.html#LE2004May04T.
Earth will plow through dust left behind in space by Comet Halley, causing the Eta Aquarid meteor shower that will peak on the night of May 5-6. There will be fewer meteors visible than usual, since the glare of the full moon will wash out the fainter ones. This shower is active for three or four days before and after its peak, beginning after midnight local time, but most of the activity will happen an hour or two before dawn for observers in North America. Many of the meteors skim through the top of the atmosphere, producing long paths. In a dark, clear sky there should be about 20 meteors per hour, most of them high overhead. They will appear to come from a point in the constellation Aquarius, which will rise in the east after midnight. More information about the Eta Aquarid shower is available at http://skyandtelescope.com/observing/objects/meteors/article_577_1.asp.
The moon will be full on May 4 (when it will be eclipsed), at third quarter on May 11, new on May 19 and at first quarter on May 27.