New Mexico State University
Astronomy graduate student Cat Wu demonstrates using a pinhole to project the sun's image. (Courtesy photo)
The first “ring of fire” solar eclipse visible in the United States in 18 years will just miss Las Cruces, but a partial or crescent shaped solar eclipse will be visible across all of the Western U.S. New Mexico State University’s Department of Astronomy, along with the Astronomical Society of Las Cruces and the Las Cruces Natural History Museum, invite the public to join them in watching this stunning event at the Mesilla Valley Mall on Sunday, May 20.
“The sun is a constant in our lives, especially in the southwest, so it is amazing to see something as dramatic as a solar eclipse happen,” said Jillian Bornak, a graduate research assistant in astronomy. “The moon’s shadow is small, so it takes the perfect alignment of the Earth, moon and sun for the moon’s shadow to fall on the Earth. The next time this arrangement will allow the moon’s shadow to cross New Mexico won’t be until 2023.”
The moon’s orbit is slightly oval-shaped, so the distance between the moon and the
Earth varies. This determines what kind of eclipse we see. On May 20, the moon will be farther from the Earth, so it will appear smaller than the sun, creating what is called an annular (or ring-shaped), solar eclipse across parts of the U.S. from Texas to Oregon for the first time in 18 years.
The path of the moon’s shadow across the Earth will start in Southern China, cross the Pacific Ocean near Alaska, race across California, and finish in northern New Mexico and West Texas. A NASA map shows the “ring of fire” eclipse should be visible in a strip of New Mexico from just north of Santa Fe to just south of Roswell. People in the southern part of the state will only catch the outer part of the moon’s shadow, so Las Cruces will see only a partial solar eclipse.
The eclipse will take four hours to complete. However, for New Mexico residents, the eclipse will only last two hours before it is interrupted by sunset. Starting around 6 p.m. on Sunday, the moon will begin to cover the sun. At 7:30 p.m., the moon will block most of the sun and the eclipse will be at its deepest. This will last about four minutes. Then, the moon will slowly uncover the sun. The show will be over at 8 p.m. when the sun sets.
Even though the moon will block 90 percent of the sun’s light, it is still unsafe to stare directly at the sun and could cause lifelong damage to eyes. NMSU astronomers caution that regular sunglasses do not provide adequate protection to look safely at the sun.
If you are unable to attend NMSU’s free viewing at the mall, there are still easy ways to safely view the eclipse on May 20. Graduate students will be handing out special sun-safe solar glasses at the Las Cruces Farmer’s Market on May 19.
A “pinhole camera” is also a safe way to watch the eclipse. You can make one with two pieces of paper or cardboard. Poke a small hole in one piece of paper, hold it up to the sun, and let the light from the pinhole shine on the other piece of paper. This projects the image of the sun like a small television.
The pinhole can be any shape. Simply hold the two sheets far enough away from each other that the image of the hole is circular. Do not look at the Sun through the pinhole.
Astronomy graduate students and museum staff will have solar telescopes set up in the southwest parking lot of the Mesilla Valley Mall from 6-8 p.m. There will be activities and free handouts at the event. Solar eclipse glasses will be on sale at the event. They are $1 each or four for $3.
For more information on the sunset solar eclipse, visit http://astronomy.nmsu.edu/eclipse or contact Bornak at firstname.lastname@example.org.