![]() Most likely you'll see somewhat lower rates than those listed. Note that the rates are for ideal conditions: very dark skies free of moonlight or light pollution, with the radiant nearly overhead. Meteor showers usually peak during the predawn hours on the dates listed below, though they're typically active a few nights before and after the peak date. In any case, the higher a shower’s radiant, the more meteors it produces all over the sky. Its radiant lies in the constellation Boötes. One notable exception to this rule is the Quadrantid shower, named for the now-defunct constellation Quadrans Muralis. for observers at mid-northern latitudes.Ī shower gets its name from the constellation where this radiant lies - for example, August's well-known Perseid shower has its radiant in Perseus, as shown in the illustration at right. The radiant of the Perseid meteor shower is low in the northeastern sky by 11 p.m. This is a trick of perspective, because all these particles are traveling in parallel - part of a vast but sparse "river of rubble" that's spread all around the comet's orbit. You'll notice the difference if you watch the sky for a half hour or so during one of these events: not only do the number of meteors you'll see go up, but also the meteors seem to fly away from a common point in the sky called the radiant. However, several times each year, Earth encounters a stream of gritty debris left in space by a passing comet, and the result is a meteor shower. On most nights a half dozen of these sporadic (random) meteors appear hourly, which is what you can expect from the meteor showers in 2017. Meteors can occur at any time on any night and appear in any part of the sky. In fact, we see a meteor's streak not because the particle is "burning up," but instead because air molecules along its path become flash-heated to thousands of degrees. That's because they strike at 30 to 70 km (20 to 45 miles) per second, and all that kinetic energy is rapidly dissipated by frictional heat. The particles themselves are not large - typically they're no bigger than big sand grains, and something the size of a pea can create a meteor that's dramatically bright. The little nuggets in Grape-Nuts cereal are a close match to the size of particles that typically create meteors in our atmosphere. ![]() Expect to shoot a lot of frames before you get this lucky.ĭerived from the Greek word meteoros (meaning "high in the air"), meteors are bits of interplanetary debris slamming into Earth's upper atmosphere at altitudes of 80 to 120 km (50 to 75 miles). ![]() He used a wide-field, 16-mm lens for a 1-minute exposure at f/2.8 with an ISO setting of 800. During the 2004 Geminid meteor shower, Alan Dyer caught a bright fireball with a tripod-mounted digital camera. The rarest of these, called a bolide, shatters into pieces during its rapid descent. If you watch the starry night sky from a dark location, a few times every hour you'll see brief streaks of light from meteors, sometimes called "shooting stars." They can catch your eye just at the limit of visibility or be dramatically bright fireballs that appear brighter than Venus and light up the nightscape around you. Everyone enjoys the brief and sometimes dazzling streaks of light from meteors, sometimes called "shooting stars." Sky & Telescope predicts that the two best meteor showers in 2017 will be the Quadrantids in early January and the Geminids in mid-December. ![]()
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