Now is the chance, after dark, to spot half the eight planets
Using nothing but the eyes nature gave you, this week you can go out after sundown and spot half of the solar system's eight official planets.
The brightest is Venus. You can't miss it shining in the western sky during twilight, with its white cloud cover lit by sunlight twice as bright as sunlight on Earth. Venus has been there in the west for months, but now it is the brightest it will get.
Right now Venus is in a special position. It forms a straight, horizontal line with the much fainter stars Pollux and Castor, the heads of the Gemini twins, to its right. Pollux is an orange giant much bigger than our sun but cooler. Castor, hotter and pure white, is actually a pair of nearly identical stars too close together to separate without a telescope.
Far down to Venus's lower right, little Mercury is putting on one of its infrequent good showings. Even so, you may have to move around a bit to find a clear view near the horizon in the right direction. And don't wait until the sky is too dark, or Mercury will have already set. Your view of it should be good around 9:10 or 9:20, depending on how clear the air is.
Next up: Saturn is much easier to find, high to Venus's upper left. Saturn is the brightest point in that whole general area. It is tinted pale yellow by unearthly chemicals in its frigid cloud tops.
Continue farther upper left past Saturn, and you will hit the fainter star Regulus, hot bluish white. Higher above Saturn, look for even dimmer Algieba.
Turn around; the fourth bright planet of evening is Jupiter, shining nearly on the opposite side of the sky. It is second in brightness only to Venus. At nightfall Jupiter glares low in the southeast; as night grows late it climbs higher toward the south. After moonrise around 10:30 this evening, you'll find Jupiter high to the moon's upper right.
Jupiter, too, is accompanied by a notable star this season. To its lower right, you will spot the fiery orange spark of Antares, one of the sky's brightest red supergiant stars. Here's a fine chance to verify the old adage that stars twinkle and planets don't. Twinkling arises not in the stars themselves but from tiny heat waves rippling through the air, usually within just a few thousand feet of your eye. A planet displays a larger disk, even though it is still a tiny dot to the naked eye. Each point on the planet's face twinkles independently of the rest, so the total usually averages out into a steady glow.
Also near Jupiter and Antares are fainter white stars of the constellation Scorpius; look below Antares and to its upper right. Along with Antares, they are part of a huge association of young stars about 400 light-years away.
Did you have any idea that this much of the outer cosmos was visible from your earthly doorstep? Even without a telescope, and even through the artificial skyglow over the city, you can do lots of amateur astronomy.
In my case, it happened at age 14 when I was hanging around the house bored on vacation. A few little events had turned my thoughts to astronomy. From a top shelf in my dad's room I pulled down an old constellation guidebook that had gone unnoticed all my life. It was H. A. Rey's "The Stars: A New Way to See Them," and no one could have arranged a luckier pick. That first evening I was hooked.
Night after clear night, I took the book out into the dark with (as it recommended) a red flashlight to read it by. One by one, I pieced out new constellations, sometimes with the help of the family binoculars where stars were too faint to show through the light pollution over Newton. Each constellation was a new Latin or Greek name to add to my growing list. Over the years, the patterns that I learned those nights have become ever-more-familiar friends.
Astronomy is all about the grandest, most mind-boggling things that exist -- everything about where we are and where we came from -- but first and foremost, it's an outdoor nature hobby. Go to the library and browse the astronomy shelf for books about the basics and guides to what's in your sky. Go as fast or as slowly as you feel like, but stick with it, and truly there will be no end in sight.
Alan M. MacRobert is a senior editor of Sky & Telescope magazine. Star Watch appears the first Saturday of every month. 