Heavy smoke from forest fires in California and British Columbia may affect how many meteors we’ll see from the Perseid shower this weekend. Two nights ago, a gap between extensive tendrils of airborne smoke made for one of the darkest skies of the past few weeks. The Milky Way was incredible, and I even spotted a few early Perseids. Then last night, even though the sky was “clear,” it appeared sickly gray with only the brightest stars poking through. The Milky Way? Gone.
Winds had blown smoke from fires in northern British Columbia 2,200 miles (3,550 km) away over North Dakota, Minnesota and Wisconsin by yesterday afternoon. Come evening, the sun was a dull, red ball barely visible to the eye before it set. The haze still lingers today. Maybe you’re seeing the same thing where you live. Smoke from the West has been reported as east as New York. From satellite photos it appears that most of the smoke is concentrated in the northern half of the country. The Deep South and Southeast aren’t nearly as affected.
Smoke dims stars and will affect the visibility of the Perseid meteor shower which reaches its peak Sunday night through Monday morning. Last night, the number of stars I could see through the smoke depended on how high above the horizon I looked. In the lower third of the sky I normally can see down to magnitude 5; last night I could only reach magnitude 3 in least light-polluted areas. Overhead, where the line of sight passes through less haze, stars of 4th magnitude were visible. Normally, I can see down almost to magnitude 6.
What to do? If fire haze dulls your skies, don’t give up on the shower. Since smoke gets progressively thicker the closer you look to the horizon, the solution is simple. Lie on your back and look straight up! That’s where the haze is thinnest and sky darkest. And to be honest, it’s a pretty comfortable position from which to watch a meteor shower.
To check on the progress and extent of the smoke during the day, click here for the current satellite photo then click anywhere on the photo for a close-up of your region. To expand the view, return to start and in the output image line change the width fo 1400 and height to 1000, then click on the image again. You can usually tell smoke from true clouds because clouds are whiter and have sharply-defined outlines. Fire smoke looks dull, hazy, wispy and ill-defined and covers large areas. When sunlight shines from a low angle like it does around sunset and sunrise, it dramatically lights up the smoke and shows how thick and extensive it truly is. For satellite images of the western U.S. and Pacific regions, click here.
The forecast for northern Minnesota is for the smoke to clear by tomorrow night for the peak. No matter where you live, watch the skies and check the satellite photos. Smoke comes and goes, and you just might get lucky. Hang in there and remember to look up. Straight up!