In the sky: Venus

Venus, the nearest planet to Earth, has long been an object of interest in the heavens. It is the brightest point-like object in the sky (for now: it only narrowly edges out the International Space Station), and aside from the occasional bright comet and glints of sunlight off of satellites, it is the third brightest object overall after the Sun and Moon.

The ancients named Venus the Evening Star and the Morning Star, because it was visible when no other stars were. In the 1600s, Galileo’s observations of the phases of Venus were crucial to proving that the planets orbited the Sun–before, there was no proof that Venus actually went behind the Sun. And today, it is still a great target for stargazers.

Venus cycles between Morning and Evening Star every 19 months, and right now, it’s moving into its Evening Star period. It’s easy to spot: just look to the west after sunset, and it’ll be obvious. The hard part is not mistaking it for a UFO.

But there are some interesting quirks to observing Venus. On November 1, Venus will be at its maximum elongation–its greatest distance from the Sun–47 degrees. Depending on your latitude, that could be as far as halfway up the sky at sunset. Around that time, it will be most possible to see Venus during the daytime. No kidding. If you know exactly where to look, you can see Venus in broad daylight because it’s brighter than the daytime sky.

I’ll post more on how to do this later, but Heavens Above is a good reference for the right direction. You should stand in a shadow where you can’t see the Sun, find the approximate place in the sky, and look carefully around that area. You should see a tiny pinprick of light, and that’s Venus. I’ve done this myself up to an hour before sunset. If you look at Venus through a telescope at maximum elongation, it will be at half phase.

On December 11, Venus will be at its greatest brightness in the sky. At this time, Venus will be at crescent phase. Even though less of the visible part of the planet is lit up, it will be closer to Earth, so that will be the brightest time. At maximum brightness, the crescent of Venus is almost an arcminute long. That means if you have 20/20 vision, you will just be able to tell that it’s not a round disk. It will be easier if you have better than 20/20 vision or better than 20/20 eye wear.

Finally, let’s remember that Comet ISON is coming in December, and if it’s half as good a show as the models are predicting, it’ll be a beautiful sight, and probably even brighter than Venus. The two objects won’t really be in the same part of the sky, but there’s a good chance that Venus will have to give up its number 3 spot for a while.


About Alex R. Howe

I'm a full-time astrophysicist and a part-time science fiction writer.
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