Astronomy magazine is predicting that this month's eclipse will be the most-viewed ever. They're basing that on the attention it's getting from American media, the good coverage our highways will give for it, the typical weather this time of year, and the number of people who will have access to the eclipse's path. They also recently published a list of facts about the eclipse. Here are a few of our favorites:
1. Solar eclipses only happen at New Moon. The Moon has to be between the Sun and Earth for a solar eclipse to occur. The only lunar phase when that happens is New Moon.
2. Eclipse totalities are different lengths. The reason the total phases of solar eclipses vary in time is because Earth is not always at the same distance from the Sun and the Moon is not always the same distance from Earth. The Earth-Sun distance varies by 3 percent and the Moon-Earth distance by 12 percent. The result is that the Moon’s apparent diameter can range from 7 percent larger to 10 percent smaller than the Sun.
3. Everyone in the continental U.S. will see at least a partial eclipse. In fact, if you have clear skies on eclipse day, the Moon will cover at least 48 percent of the Sun’s surface. And that’s from the northern tip of Maine.
4. Cool things are afoot before and after totality. Keep your eyes open during the partial phases that lead up to and follow it. Around the 75% mark, you’ll start to notice that shadows are getting sharper. The reason is that the Sun’s disk is shrinking, literally approaching a point, and a smaller light source produces better-defined shadows. At about 85% coverage, someone you’re with will see Venus 34° west-northwest of the Sun. If any trees live at your site, you may see their leaves act like pinhole cameras as hundreds of crescent Suns appear in their shadows.
5. Nature will take heed. Depending on your surroundings, as totality nears you may experience strange things.
Look: You’ll notice a resemblance to the onset of night, though not exactly. Areas much lighter than the sky near the Sun lie all around the horizon. Shadows look different.
Listen. Usually, any breeze will dissipate and birds (many of whom will come in to roost) will stop chirping. It is quiet.
Feel. A 10°–15° F drop in temperature is not unusual.
6. Maximum totality is not the longest possible in 2017. The longest possible duration of the total phase of a solar eclipse is 7 minutes and 32 seconds. Unfortunately, the next solar eclipse whose totality approaches 7 minutes won’t occur until June 13, 2132. Its 6 minutes and 55 seconds of totality will be the longest since the 7 minutes and 4 seconds of totality June 30, 1973.
7. Only one large city has a great view. The 609,000 people lucky enough to live in Nashville, Tennesee, will experience 2+ minutes of totality. According to Astronomy, Denver will only reach 92% totality, which means Gillette is a better place to be during the eclipse!
Get your plans together for the eclipse! Travel may be difficult and interruptions in delivery services may make any last minute necessities difficult. Make sure your prescriptions are filled the week before, and you have plenty of groceries.
And make sure you know the "official" Wyoming Eclipse hashtag brands to use: #WYEclipse #ThatsWY and #WYSkies.