Stargazing in the Parks
Constellations are stories in the sky—many depict figures from Greek mythology, including the zodiac. Brush up on a few of these tales before your trip, and—armed with the star chart (right)—you'll be an instant source of nighttime entertainment.
The stars appear to rotate around Polaris, the North Star, in fixed positions relative to one another. To get your celestial bearings, first find the bright stars of the Big Dipper. An imaginary line drawn through the two stars at its end (away from the handle) will hit Polaris. You can also follow the path of the dipper's handle and "Arc Arcturus" to the bright star in the constellation Bootes.
Myriad astronomy books and Web sites have additional star charts; National Geographic has a cool interactive version with images from the Hubble Space Telescope (www.nationalgeographic.com/stars/chart).
Stars twinkle, planets don't (because they're so much closer to Earth, the atmosphere doesn't distort their light as much). Planets are also bright, which makes them fairly easy to spot. Unfortunately, we can't show their positions on this star chart, because planets orbit the sun and move in relation to the stars. To search for planets on your trip, visit a stargazing Web site (stardate.org/ or www.space.com/spacewatch) before you head to the park.
The easiest planet to spot is Venus, the brightest object in the night sky besides the moon. Look for it just before sunrise or just after sunset; it'll be near the point where the sun is rising or setting. Like the moon, Venus goes through phases—check it out through a pair of binoculars. You can also spot Mars, Jupiter, Saturn, and Mercury—with or without the aid of binoculars.
It's hard to match the magic of a meteor shower, the natural firework display that occurs as Earth passes through a cloud of comet debris. These pieces of space junk—most the size of a grain of sand—hit our atmosphere at high speeds, and the intense friction produces brief but brilliant streaks of light.
Since our planet passes through the same patches of interstellar junk each year, it's easy to roughly predict when the major meteor showers will occur. Notable ones include the Perseids (mid-August), the Orionids (late October), the Leonids (mid-November), and the Geminids (mid-December); check astronomy Web sites for optimal viewing times. Each shower is named after the point in the sky where meteors appear to originate. If you're not visiting during a shower, don't worry—you can spot meteors any time of the year.
Right now, there are about 2,500 satellites (operative and inoperative) orbiting the Earth—and you can catch a glimpse of one with a little practice. Satellites look like fast-moving, non-blinking points of light; the best way to spot one is to lie on your back and scan the sky for movement. Be on the lookout for satellites an hour or two before or after sunset (though you may see them at other times as well).
You can take the guesswork out of the search with a few cool online tools (www.nasa.gov or www.heavens-above.com). Select your location, and these Web sites will help you predict—down to the minute—when certain objects will be streaking overhead. It's especially worthwhile to use these sites to look for the two brightest satellites: the International Space Station and the space shuttle.