Sunday, April 29, 2012

Annular Event

This post will also be found in Tehachapi's The Loop Newspaper.  
Not “annual”. Annular. Though we get both words from the Latin, annual means yearly, annular means in the form of a ring. 

Solar eclipses occur when the Moon moves between the Earth and Sun blocking out the Sun for a brief period of time. As a side note, solar eclipses can only occur during a “new” moon. Which makes sense since the side facing us can't be getting any sunlight. 

When the Moon completely blocks out the Sun we have a total eclipse. This happens because the orbit of the Moon places it directly between the Sun and Earth. So total eclipses are more rare than partial eclipses, which occur when the Moon merely blocks out part of the Sun.

But this May (May 20th to be exact) we're going to have a partial total eclipse. OK, I made that term up. What we're going to have is an “annular” eclipse. These occur when the Moon is correctly positioned for a total eclipse, but due to variations in the orbit of the Moon, it is a little further away from the Earth. Since it is further away it blocks less of the Sun. So there will be a ring of the Sun still visible when the Moon is directly between the Sun and Earth.

But like all solar eclipses, you won't be able to see it from just anywhere. We won't be able to see it from Tehachapi. (Darn.) However, we're in luck this time. Northern California is in line to see this eclipse. Eureka and Redding are pretty close to the centerline for this eclipse. As are Lake Tahoe and Reno. 

Depending on the weather there should be come good opportunities to see this annular eclipse up north. Given the how cloudy and rainy it can be along the coast, that might not be the best choice. But somewhere along the line from Eureka to Reno, there should be some good spots to watch the eclipse. 

So if you decide to go, to Redding, then the annular part of the eclipse will start about 6:26 pm PDT and will last about 4 and a half minutes. If you pick Reno, then you'll have about the same amount of time with the annular part of the eclipse starting about 6:31 pm PDT.

Now even total solar eclipses can still produce eye damaging amounts of light (even when it seems dark), so watch with care. One of the best, easy ways to watch is to take two index cards, poke a pinhole through one and use it to “project” the Sun onto the other card. Otherwise, make sure you have appropriate solar filters or projecting device. You can get either with certain telescopes.

Now if you insist on seeing the eclipse with your naked eyes, unprotected if you will, head out to West Texas. You'd be able to see the eclipse in Lubbock at sunset. Stare at the sunset and enjoy the ring. I'm hoping to be able to go up north to see this eclipse. Maybe I'll see you there.

No comments:

Post a Comment