With daylight saving time still in effect across most of the United States and Canada, the sun is now rising at many localities after 7 a.m. local time. That means dawn is coming late, so a lot of people may head out to work or school these days under a fairly dark sky.
On Friday morning (Oct. 12), early risers will be in for a treat as the two brightest objects in the night sky approach each other to make for a lovely celestial scene -- something to admire while you're perhaps waiting for the bus or train.
Looking low toward the east-northeast beginning around 4 a.m. local time, you'll see a narrow waning crescent moon, just 12-percent illuminated. Situated about 7 degrees above and to its left will be the brilliant planet Venus. (Your clenched fist extended at arm's length measures roughly 10 degrees across).
By the time sunrise comes about three hours later, this eye-catching pair will appear about one-third of the way up from the southeast horizon to the point directly overhead (the zenith). [Amazing Photos of Venus, the Moon and More]
Keep in mind that when you're looking at the moon, it lies some 232,000 miles from Earth. Meanwhile, Venus is more than 450 times farther away from us, at a distance of 105 million miles.
Here's a question you might want to ponder early Friday as you gaze at the celestial duo: Which is the brighter of the two?
At first glance you might think it's Venus, which gleams with a sharp and steady silvery light. In fact, in very dark locations, this beacon of the night can cast a faint but distinct shadow. At magnitude -4.1, Venus currently shines 11 times more brilliantly than Sirius, the brightest star. (In astronomy, lower magnitudes signify relatively more luminous objects.)
But the planet still doesn't outshine the slender sliver of a moon, which will be just three days from its new phase.
In fact, the moon is more than 27 times brighter than Venus. The reason this may be difficult to believe is that, whereas all of Venus' light is condensed into a dot in the sky, the light of the moon is spread out over a much larger area.
Keep your eyes on the moon and Venus as the sky lightens up. After sunrise Friday, you'll still be able to see the moon easily. And using Earth's nearest neighbor as your benchmark, you should also have little trouble spotting Venus, which will appear as a tiny white speck against the blue daytime sky. See how long you can follow them through the course of the day.
Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for The New York Times and other publications, and he is also an on-camera meteorologist for News 12 Westchester, New York.
- October 2012 Night Sky Guide (Sky Map Gallery)
- How to Observe the Moon (Infographic)
- Best Beginner Astrophotography Telescopes
Copyright 2012 SPACE.com, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.