Stargazers, you may want to plan on calling in sick on Friday. This year's Perseid meteor shower is shaping up to be the best since 2009.
"Forecasters are predicting a Perseid outburst this year with double normal rates on the night of Aug. 11–12," said Bill Cooke with NASA's Meteoroid Environments Office. "Under perfect conditions, rates could soar to 200 meteors per hour."
Why the outburst? According to Cooke, each meteor in the Perseid meteor shower is actually a tiny piece of debris — no bigger than a silver dollar piece — trailing behind the 16-mile wide Swift-Tuttle comet, which orbits the sun every 133 years. As it orbits the comet spits off bits of dust and ice, which we know as the Perseid meteor shower.
In most years, the Earth just grazes the edge of this debris stream, but occasionally, Cooke said, as the comet intersects with Jupiter's orbit, the debris stream bunches up.
“Jupiter’s gravity causes the particles in that loop to bunch up and become more concentrated,” he said.
And while the Perseid meteor shower is technically visible in the sky through Aug. 25 this year, the early morning hours of Aug. 12 marks the peak of this year's activity stream.
But even in a high activity year such as this one, viewing the meteor shower can be tough, especially in highly populated areas like the Portland and Seattle metro areas. And don't expect to catch some Perseids burning in the sky by stepping out on your porch for five minutes. To get the most out of this year's show, head away from light pollution — far, far away. The darker the sky is, the clearer your view of the meteor shower will be. And prepare on spending awhile outside.
"If you can see the Milky Way, then you have what is considered a good dark sky," said Jim Todd, director of space science education at the Oregon Museum of Science and Industry (OMSI) in Portland.
Todd said the best hours for viewing are between midnight and just before dawn, with around 3 a.m. being the darkest point in the night. If you can't escape the light pollution of a city, you still should be able to see some action up in the sky — but it'll be more like 10 to 15 meteors per hour instead of the projected 200, Todd said.
If you can get out to a dark area, put your back to the moon and look toward the northeast portion of the sky. Todd said as long as you are looking in the shower's general direction, you should be able to witness some spectacular bursts under the proper conditions.
If you need some help figuring out where to go to get the best views, Todd suggests getting out towards the coast or east of the Cascades. Remember, darkness is key and you want a clear view of the sky: don't look toward mountains or tall obstructions.
Want an expert by your side? OMSI is hosting a pair of star parties at Rooster Rock State Park in the Columbia River Gorge and L.L. "Stub" Stewart State Park east of Timber, Oregon. Both are free and open to the public, but space is limited, so get there early (the parties begin at 9 p.m. on Friday, Aug. 12).
Oh, and as for the massive comet behind all of this magic, don't worry, we're safe.
"The closest we show the comet approaching Earth for the foreseeable future (a couple of centuries) is in August 2126, when it will come no closer than 14 million miles from Earth," said Lindley Johnson, NASA's planetary defense officer.