After an absence of just over a year, the “evening star” is poised to wow skywatchers again. Venus is visible just after sunset now for keen viewers and will soon be unmistakable in the evening sky. Before long, you’ll even be able to spot it during broad daylight.
VENUS WAS a brilliant morning star earlier this year. It passed superior conjunction, appearing to go behind the sun as seen from Earth, back on Aug. 18. Since then, it has been ever so slowly working its way out from the brilliant glare of the sun. In recent days, some ambitious, skilled observers have caught a glimpse of it, very low near the southwestern horizon just after sunset.
During this upcoming week, it should become visible even to inexperienced sky watchers as a bright starlike object very low in the western twilight. On Friday evening, Venus sets about 20 degrees south of due west (10 degrees is roughly equal to the width of your fist held at arm’s length) and just more than 45 minutes after sunset; a clear and unobstructed view of the southwest horizon is a must for anyone hoping to spot the planet.
By Nov. 1 the situation will have improved slightly, with Venus setting about 55 minutes after the sun. From then on, Venus will become an easy target.
START THIS WEEKEND
Here is a challenge to all skywatchers: On Sunday evening, try looking for Venus immediately after sunset when it will appear to lie just off to the right of a very young crescent moon, less than two days past new phase. Binoculars will certainly help. Venus itself may appear as a surprisingly brilliant spot of light very low near the southwest horizon.
Venus is so bright that the sky does not have to be dark for it to appear.
Continuing to swing east of the sun during November — a gradual movement hardly perceptible from night to night — Venus will soon become plainly visible in the west-southwest evening sky even to the most casual of observers.
Our sister planet will set at least an hour after the sun by the end of the first week of November. It will shine at magnitude -3.9 on the astronomers’ scale. Lower numbers are reserved for the brightest objects, and Venus reigns in brightness among stars and planets. Only the sun and moon outshine it.
WINTER AND SPRING
Venus slowly rises higher each evening to adorn the western evening sky all during the upcoming winter and early spring. By New Year’s Day, it will set as late as 2½ hours after the sun.
Venus reaches greatest elongation — its greatest angular distance, or 46 degrees to the east of the sun — on March 29. From then on, into mid-April, it will be setting more than four hours after the sun. It will be brightest in midspring as it heads back down toward the sun, reaching its greatest brilliancy for this apparition on May 2 at magnitude -4.5.
Venus, in fact, will be so bright at this stage of the game that it can be easily perceived with the naked eye in a deep blue, haze-free afternoon sky. That’s right, during the day! After twilight ends, from a really dark site, it will be capable of casting faint, yet distinct shadows.
JUST A PHASE
Much like Earth’s moon, Venus goes through phases.
Between now and May 2004, repeated observation of Venus with a small telescope will show the complete range of its phases and disk sizes. The planet currently appears almost full (96 percent sunlit on Oct. 21), and thus appears as a tiny, dazzling gibbous disk. It will become noticeably less gibbous by midwinter.
By the end of March, Venus reaches what’s called dichotomy, displaying a “half moon” shape.
Then, for the rest of the spring it will be a large crescent as it swings nearer to the Earth. Indeed, those using telescopes will note that while the Earth-Venus distance is lessening, the apparent size of Venus’ disk will grow, doubling from its present size by March 17. When it has doubled again in size on May 8, its large crescent shape should be easily discernible even in steadily held 7-power binoculars.
MAY AND JUNE
As May progresses our bright sister planet will get rapidly lower in the twilight, soon to disappear. It will actually start the month almost 40 degrees high in the west at sunset, but will plummet to a sunset altitude of only around 10 degrees by month’s end (for midnorthern latitudes).
Venus then quickly fades, vanishing from completely from view during the opening days of June.
The stage will then be set for the unusual spectacle of Venus appearing to cross in front of the sun at its June 8 inferior conjunction.
During the third week of June, Venus re-emerges as a “morning star” appearing just above the east-northeast horizon. Climbing progressively higher each morning, Venus will then shine very prominently in the morning sky right on through the late fall of 2004.
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