A total solar eclipse is when the moon comes directly between Earth and the sun. This happens fairly frequently, roughly twice a year. However, because the moon’s shadow is so small, any particular place on Earth will rarely see a total solar eclipse.
Only those within the dark band on the NASA map will see a total solar eclipse. The rest of the continent will see a partial solar eclipse, where the moon will cover a portion of the sun. Fort Collins, for example, will see 96 percent of the sun covered by the moon.
Total or Partial?
There is nothing more visually spectacular than a total solar eclipse. A partial eclipse does not even come close. A 96-percent partial eclipse is not 96 percent as good as a total solar eclipse, although still pretty impressive.
Total solar eclipses are also rare. In the next 50 years, North America will see four more – 2024, 2044, 2045, and 2052. The 2045 eclipse path will go through Colorado. So to see another total solar eclipse, you are either going to have to travel or wait another 28 years.
Observing the Total Eclipse
From Colorado, you will need to travel to Wyoming or Nebraska, somewhere along the totality pathway. Anywhere will do, but I would strongly advise you to avoid the obvious, like Casper, Wyo. Wyoming’s population is expected to triple this Aug. 21. That’s an extra million people, many of whom are going to drive Interstate 25. Back roads and small towns will help you avoid what will probably be a massive traffic jam on I-25.
Time of the Eclipse Depends on Your Location
For Casper, the eclipse will start at 10:22 a.m. From the start to totality, you will see the moon progressively cover more and more of the sun. Totality begins at 11:42 a.m. and ends just under 3 minutes later at 11:45 a.m. The eclipse will be completely over at 1:09 p.m. If you are east of Casper, the start times will be a few minutes later than Casper’s times and if you are west of Casper, the start times will be a few minutes before.
Total Eclipse is Safe to View
During totality, the sun is perfectly safe to look at with the naked eye (or even with a pair of binoculars). Look for the white colored crown of the solar corona surrounding the shadow of the moon and maybe even the pinkish colored chromosphere and prominences surrounding the shadow of the moon. You will also be able to see planets and the brightest stars, Venus will be to the right of the sun and Jupiter will be on the far left. Mars and Mercury also will be present, but might be too dim to see easily. Your eyes won’t have time to the dark adapt to see anything else.
Baily’s beads and the diamond ring are phenomena that occur right as totality begins and ends, as the last (or first) rays of sunlight come through valleys on the moon. They signify when you should take off and put back on your solar glasses.
One rarely seen and not completely understood phenomena seen during totality are shadow snakes. These are rippling bands of dark shadow seen on flat surfaces, like sand, road surfaces or the sides of vehicles.
Need Eye Protection for Partial Eclipse
If any part of the sun is visible, even a tiny sliver, it is not safe to look at it. The sun’s ultraviolet light will do permanent and cumulative damage to the retina of your eyes. This means that from the start of the eclipse to totality and from the end of totality to the end of the eclipse, you must have eye protection. A pair of solar eclipse glasses is essential equipment to look at the sun safely outside of totality.
Time of Partial Eclipse
It will grow dim at the height of the partial eclipse (around 11:45 a.m. for Fort Collins), but it won’t grow completely dark. While none of the astronomy faculty will be in Fort Collins for the eclipse, we are planning to have a solar telescope set up at Sunlight Peak Observatory from 11 a.m. to 12:30 p.m.
What if it is Cloudy?
That would be sad! There is no point in trying to observe a partial eclipse during cloudy conditions. If it is cloudy in the path of totality, it will still become dark, but all of the other phenomena will not be visible. The current forecast for the Aug. 21 is favorable but not perfect.
Any other questions?
If you have any other questions, please do not hesitate to ask us: Mike Smith (firstname.lastname@example.org) Andy Caldwell (email@example.com) or Joe Collins (firstname.lastname@example.org).