Week of January 22-28, 2017

If you're like me, you've been marveling at the brilliant star now appearing in the western sky at dusk. You may also have noticed that it seems to be closing in on another fainter star just above it.

Well, if they were truly stars, I'd be worried. But they're not; they're planets. The lower of the two is Venus, the most brilliant planet of our solar system, and the upper (and much fainter) is the red planet Mars.

Mars and Venus appear to be drifting closer because they, along with our Earth, orbit the sun, and our constantly changing viewpoint makes them appear to drift against the more distant and fixed stars.

Early next week, another solar system body will enter the scene: the moon. Since our celestial neighbor orbits the Earth only once a month, we can detect its movement quite easily.

Think about it this way: The moon makes its 360-degree journey around our planet in just about one month — or, to keep the arithmetic simple, about 30 days. To do so, it must move through the sky about 12 degrees per day, and anyone who goes outside on two consecutive evenings can certainly see this change in position.

What's more, to make this journey, the moon must move one-half degree per day; that's equivalent to its apparent diameter in the sky. So if you're really perceptive, you might even notice this as the moon drifts by other more distant celestial bodies.

If you have a clear sky and a very low horizon to the west, you might get your first glimpse of the superthin crescent moon below Venus (and quite close to the horizon) shortly after sunset on Jan. 29. By the next night, however, the moon will have drifted eastward along its orbit, and you'll see it as a slightly thicker crescent a bit closer to Venus.

But it's the night of Jan. 31 that I'm looking forward to because at dusk, the crescent moon will form a tight triangle with Venus and Mars.

Of course, this is all purely an illusion — these bodies are really millions of mile apart. But it sure results in a pretty view. In fact, if you wish to see something even prettier, aim binoculars at the trio and you'll see all three in the same field of view.

Wow!

You might even like to capture the scene in a photograph. You won't need fancy equipment, but a zoom lens and tripod will definitely help.

This week the trio appears low enough in the sky at dusk for you to frame the scene with a foreground subject, like a dramatic tree, a building, a sculpture or a person. If you shoot around 30 to 40 minutes after sunset, you can probably trust your camera's automatic settings. If not, try setting your camera to ISO 100 or 200 and shooting at about 1/3 of a second at f-stop 8. You'll need to adjust settings as you go, however, since the sky light changes rapidly at dusk. Don't be afraid to experiment.

Enjoy the sky show, and please email me if you get some nice photos. I'd love to share in your success!

View the moon, Venus and Mars at dusk this week.

Visit Dennis Mammana at www.dennismammana.com. To read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.