A Bright Planetary Trio at Dusk

only appear along the same line of sight; on that evening the two will actually be separated by nearly 410 million miles.

This will be a great time to aim a low-powered telescope in their direction since both will appear in the same field of view. Before that day comes, however, another solar system body will enter the scene: the moon.

At dusk on Tuesday, Feb. 21, the moon may be tough to spot, but if you have a very low horizon below Venus, you can scan the area with binoculars during dusk and you might be able to catch a glimpse.

If you miss it, don’t worry. The following night you’ll easily see a thicker and brighter crescent moon complete with a full disk of “Earthshine” -- light reflecting onto the lunar dark side from the Earth itself -- lying just to the left of Jupiter.

Aim binoculars toward this pair and you’ll be stunned by how three-dimensional the scene appears. While this is purely an optical illusion, it sure does produce a pretty picture.

And speaking of pretty pictures, this is a great time to take photos. You don’t need fancy or expensive equipment; just a camera and tripod -- even a smartphone will do fine. You’ll find that zooming in a bit will produce a much better shot, though.

If you shoot half an hour or so after sunset, you can probably trust the automatic settings of your camera or phone. If not, try setting it to ISO 100 or 200 and shooting 1/3 of a second or so at f/8. Unless you’re using an automatic mode, you’ll need to adjust settings as you go since the light changes rapidly at dusk. Enjoy this week’s planetary sky show, and please email me if you pro-