Starwatch: It's solar eclipse time!
Thousands and thousands of sky watchers, including yours truly, have waited a long time for this Monday's total solar eclipse.
There are many people traveling to the narrow band of totality that stretches diagonally across the 48 contiguous states from Oregon to South Carolina. It's no more than 70 miles wide along most of the band.
Depending on where you are along the band, totality will occur between 10 a.m. to 3 p.m. The west end of the band will see morning totality and the eastern portion will have afternoon totality. The length of totality varies from 2 to a little over 2 1/2 minutes. The maximum duration of totality will be 2 minutes and 40 seconds around Carbondale, Illinois, near the Missouri border, but honestly anywhere along the middle of the totality band will be only seconds shy of that. You'll never forget what you witness in those brief moments.
Total eclipses of the sun occur when the moon briefly covers the face of the sun in its monthly orbit around Earth. They occur about twice a year on average somewhere around the world, when the moon gets exactly in a line between the Sun and a narrow swath on Earth. Since the celestial disks of the sun and the moon are about the same size in the sky this is a spectacular but rare show. On average, any one spot on the Earth experiences a total solar eclipse once every three or four centuries. The last time we had this extensive of a total eclipse across the U.S. was in 1918 at the end of the first World War.
On either side of that band most of the rest of the country will see a decent partial eclipse. The closer you are to the totality band, the more the sun's disk will be covered by the moon. In Rochester, 85 percent of the sun's disk will be covered around 1:09 p.m. on Monday.
Photographing either a total or partial eclipse can be a lot of fun, but you must protect both your eyes and your camera. There's a lot of great information on how to do this on the internet. One of my favorite sites is B&H photo. Just browse: " How to Photograph a Solar Eclipse ."
Personally, I'm not all that interested in photographing the eclipse. I strongly urge you if this is your first total eclipse and you're not all that much of photographer, just enjoy it! That 2 minutes and change during totality goes by so fast! There's going to be a plethora of photos being taken by folks much more skilled than me, and most of you. I can tell you from experience that I think it's most rewarding to just witness it with your protected God-given eyes.
During the partial eclipse, before and after totality, you'll need special eclipse glasses to safely watch the moon creep across the sun's face. You never want to stare at the partially eclipsed sun without them! You can really damage your eyes, or worse. I hope you already have a pair, and if you don't it might not be too late. I have seen them in some stores. I also want to warn you to never, ever, ever, ever view the partial eclipse with binoculars and telescopes, even if you're wearing special eclipse glasses. Blindness can set in almost immediately.
Make sure you don't spend the entire time staring at the sun through your eclipse glasses, especially if you're in the band of totality. Turn away from the sun and observe the landscape around you. Watch the diminishing daylight and changing color of the sky, avoiding the sun of course. If you're lucky enough to be in the totality band you can actually see the moon's shadow migrating across the landscape. There's no way to photograph that. You just have to see it. You'll also feel the temperature dropping.
Only during totality is it safe to take off eclipse glasses and view with binoculars and telescopes. It will blow your mind. You'll easily see flares and prominences churning and emanating from the sun's violent surface. The sun's corona, the outer atmosphere of our closest star, will also be clearly visible. The most important thing to remember is to set a stopwatch with an alarm and STOP your telescope or binocular viewing at least 30 seconds before totality ends. Also remember to take a few seconds here and there to check out the sky during totality. Bright stars and planets pop out and all along the horizon the skies take on a weird twilight color.
If you can't get ahold of eclipse glasses, all is not lost. You can also use the projection method to keep up with the eclipse. Get a piece of white cardboard and punch a pencil diameter hole in the center of it. With your back to the sun, hold the piece with the hole in it so the sunlight shines through onto another piece of white cardboard. Use the shadow of the cardboard to line it up. You should be able to see an image of the partial eclipse on the blank sheet with absolutely no danger.
Instead of a piece of cardboard with a hole in it, you can also use a cooking spoon with holes in it and see multiple images of the solar eclipse. In fact, leaves on trees can have the same effect, as the space between them can produce many, many images of the eclipse on the ground or on the side of a house or other buildings.
Wherever you end up watching the eclipse, pray for clear enough skies. The next total eclipse we have in the U.S. won't be until 2024, and one as extensive as this one won't happen again until 2045.