This blog reports events and interesting tidbits from Rensselaer, Indiana and the surrounding area.

Sunday, June 3, 2012

A Sun day adventure

As I mentioned in an earlier post, I was recently out of town and far away, in Utah (and Nevada). While I was there, something special happened--there was a solar eclipse. Unfortunately, it was not a total eclipse, but a less dramatic annular eclipse.

Just in case you do not know your astronomy, an annual eclipse is an eclipse in which the moon passes in front of the sun, but its disk is too small to totally block it. The reason this can happen is that the moon travels in an ellipse around the earth, and its distance varies as it "circles" the earth. For this eclipse, the moon was at its far point (or apogee) in its path.

Great Basin National Park in eastern Nevada had made preparations for the big event, and there were plenty of people who decided to view the spectacle from the parking lot of its visitor's center.
The park ordered special solar glasses, which this boy is holding, but they sold out before I could buy one. However, my son-in-law had access to a couple of welding helmets, and they were enjoyed by quite a few people
The park had set up several telescopes for viewing. Naturally they had to have filters. (I heard that someone tried to look at the sun with binoculars using the solar glasses, and the sun melted them.) People could see sunspots using the telescopes.
One of the telescopes that the park had was hooked up to a computer, and people could see the sun on the display.

I was able to adjust a camera to take a picture through the welding helmets. I set the ISO to 800, the shutter speed to 1/2000 of a second, and the F-stop to 2.8, and I was able to get an image of the start of the eclipse.
A bit later I took a picture through the second welding helmet, which had a greenish tinge.
Near the end of the event, someone figured out that you could take the dark glass out of a helmet, clean it, and get much clearer views.

Below you can see what the eclipse looked like during the two minutes in which the moon was directly in front of the sun. A park ranger and a fellow who had been giving programs dressed as Galileo present the eclipse to the crowd.
So I do not have any pictures of the ring of fire--the clouds ate the eclipse. It did not get dark--people who did not know that there was an eclipse going on were unlikely to have noticed anything unusual. Even ten percent of the sun gives off a lot of light.

After the sun dropped below the cloud, I was able to get a shot of the moon leaving the sun's disk.
Rensselaer had an annular eclipse on May 10, 1994. I did not have a welding helmet or a camera that could get good pictures, so I had to take pictures of the images on the ground. The leaves of the trees act as pinhole cameras, and you could see the eclipse everywhere under the trees. I did not get similar pictures in Nevada because the Visitor's Center did not have good trees and also the sun was very low in the sky. The picture below is from Rensselaer, May 10, 1994. Do you remember this eclipse? It also was an annular eclipse.
(This week we will have a transit of Venus--a rare event.)

1 comment:

Ed said...

The old ramp! Wow, glad you could find that picture, I don't remember the 94 eclipse though