Named because they come from the direction of the constellation Perseus, the meteors are actually the stream of debris cascading from the comet Swift-Tuttle, which orbits the sun once every 133 years.Because there's a waxing crescent moon just now, the Perseids should be visible in most of the country where skies are clear.
Astronomers suggest driving away from city lights and finding a dark spot with good vantage of the entire sky, preferably at an angle so you're looking up at the sky without craning your neck.While the eye adapts to the dark within 10 minutes, a full switch to night vision can take up to 45 minutes, so the falling stars will become brighter and more visible as the night wears on. Be careful not to place yourself where you see oncoming car headlights, which can 'reset' the eyes for light, meaning it will take another 45 minutes to get full night vision back.
NASA astronomer Bill Cooke will hold a Web chat from 11:00 p.m. tonight to 5 a.m. EDT about the Perseids and how best to view them from the Marshall Space Flight Center. Most of the meteors in the shower Americans will see tonight and tomorrow night are from a filament of dust from the comet that streamed off in 1862.
Humans have been seeing the Perseids for at least 2,000 years and are associated with the comet Swift-Tuttle, which orbits the sun once every 133 years. The Earth passes through the tiny debris cloud that trails the comet every August. The particles of ice and dust burn up as they enter the Earth's atmosphere, creating a beautiful shower of meteors.
NASA will also be running a live feed of the shower beginning as darkness falls on the East coast.
