DETROIT – The annual Perseid Meteor Shower began last night with an hors' doeuvre of meteors, and some of you tweeted me last night and this morning that you saw some.
Our best chance to see a bunch of them is tonight!
If you missed my article yesterday, allow me to repeat for those seeing this for the first time: Meteor showers are always so much fun to tell you about, because they are one of those heavenly highlights that you don't need a telescope or even binoculars for. In fact, you'll MISS them if you try using magnification. This particular meteor shower is always a popular one due to it happening during the summer when kids are out of school and the weather is warmer.
So what are meteors?
Actually, they are technically called meteoroids. Surprisingly, most meteoroids are little pieces of rock from space that are about as big as a single grape nuts cereal nugget! They hit our atmosphere fifty to seventy-five miles up at an astounding 25,000 to 160,000 mph (evening meteoroids tend to be slower than ones that arrive in the late night hours). When the meteoroid collides with air molecules, its high level of kinetic energy rapidly ionizes and excites a long, thin column of atmospheric atoms along the meteoroid's path, creating a flash of light visible from the ground below. This column, or meteor trail, is usually less than a yard in diameter, but will be tens of miles long.
Annual meteor showers like the Perseids occur because the earth passes through the stream of debris leftover when comets flew by a long time ago (the debris trail that we're passing through now is from Comet Swift-Tuttle). If we pass through a particularly dense part of the debris trail, then we can get the rare meteor storm…I'd love to see one of these just once in my life. But the Perseids generally are a meteor shower, with perhaps a meteor per minute visible during its peak. By the way, here's a Paul Gross tip that you'll thank me for: if you just stand there looking up for Perseids, your neck will get sore really quick. Lie down on a lounge chair or blanket facing northeast, and you'll be SO much more comfortable. Last night, I laid on my driveway…it was so nice out there, and will be again tonight.
So, where and when do we look?
The best time to watch for the Perseids is between midnight and dawn, because this is when the part of the sky where the meteors originate from is above the horizon. Can you see a few in the evening? Yes. But the best show is after midnight. Just face northeast, and look up…that's where most of them will be. If you don't know what direction northeast is, look for the sideways "W" in the sky -- that's the constellation Cassiopeia, and the Perseids originate from that general area of the sky.
And this year will be a good year to watch, because we'll have no moonlight to wash out the fainter meteors -- as long as the weather cooperates, which is a great segue to begin the forecast.
Forecast:
Today's fair weather cumulus clouds will shrivel up at sunset, leaving us with crystal clear skies for the first half of the night. We will see some clouds return after 2:00 or 3:00 AM, so Perseid watchers will fare better in most areas between midnight and 3:00 AM as opposed to later -- but if you're up early and skies are clear, that's the best time to watch. Some of us may see a late night shower, but some of us won't. Lows near 60° (15° Celsius for you Canadians). Light and variable wind.
Any early morning showers will quickly end first thing Thursday morning, and we'll see partly cloudy skies the rest of the day. Highs in the low to mid 80s (28° Celsius), and you'll notice the humidity creeping up during the day. Southwest wind at 10 to 15 mph. Thursday's sunrise is at 6:38 AM, and Thursday's sunset is at 8:37 PM.
Showers and thunderstorms are likely at some point Thursday night, with a rogue strong storm not out of the question. Lows in the upper 60s.
Showers and thunderstorms are possible periodically during the day on Friday into Friday night, with highs in the mid 80s, and lows Friday night in the mid to upper 60s.
Saturday looks to be mostly sunny for most of us. The only hang-up is that today's computer models are slightly slowing down the progress of the Friday night cold front. If it slows any more, then some of you well south of 8 Mile may start Saturday with a shower or thunderstorm, but those should quickly move out. This is a very tenuous part of the forecast -- I'll update you on this tomorrow. Highs Saturday in the mid 80s, and it'll be humid.
Mostly clear and warm Saturday night, with lows in the mid to upper 60s.
Mostly sunny and continued hot and humid on Sunday, with highs in the mid to upper 80s.
Mostly clear Sunday night, with lows near 70°.
Mostly sunny to start the day on Monday, then thunderstorm chances ramp up sometime during the afternoon (strong storms are possible). Highs in the mid to upper 80s.