Archive for August 17, 2017

08/17/2017 – Ephemeris – How do you view the solar eclipse if you don’t have eclipse glasses?

August 17, 2017 1 comment

Ephemeris for Thursday, August 17th. The Sun rises at 6:47. It’ll be up for 13 hours and 56 minutes, setting at 8:44. The Moon, 3 days past last quarter, will rise at 3:13 tomorrow morning.

OK here you are 4 days before the solar eclipse and you can’t find any eclipse glasses. What do you do? The answer is project the Sun’s image. I personally do not use eclipse glasses. The projected image is bigger and I don’t get a crick in my neck.   The Sun is bright enough to project itself on a screen. A telescope with a low power eyepiece or one side of a pair of binoculars project a wonderful image of the Sun. An envelope with a quarter to half-inch hole holding a mirror, can project the Sun on the side of a building some feet away. If worst come to worst take a colander, and use the holes to project a multitude of Suns. We’ll be at Friday Night Live tomorrow on Front Street in Traverse City to demonstrate these methods. Come between 5:30 and 7:30 p.m. for demonstrations if it’s clear.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.


Two pinhole solar projection methods

Two pinhole solar projection methods. Credit NASA.

Binocular projection

I’m demonstrating using binoculars to project the Sun. The lens cap is on the unused side.  The shade in front creates a shadow to project the Sun in.  Be careful to not let anyone attempt to look through the projection side.  A kid tried to do it when I was demonstrating the technique at the last Sun ‘n Star Party. I had to push him away before he was able to look. Photo by Bea Farrell (granddaughter).