Witness a partial solar eclipse on Sunday

Much of the western U.S. will witness an annular or partial solar eclipse this coming Sunday. Because the moon is near apogee (its farthest distance from the Earth this month), its disk will be too small to cover the sun completely, so that at maximum totality the solar rim still will be visible. Such eclipses are called annular, from “annulus,” the Latin word for “ring.” People along the central path of the moon’s shadow in northern California, southern Oregon, Nevada, southern Utah, Arizona, New Mexico, and part of Texas will see the annular stage; in North Dakota we shall see only a partial solar eclipse, but that still will be worth viewing with some precautions.

Here is a timeline:

Today, 11:13 a.m.: The Moon reaches apogee at a distance of 252,555 miles from the Earth. Even though it will head back slowly toward our planet, at the greatest maximum of this annular eclipse the moon will be able to cover only 93.29 percent of the sun’s disk.

Sunday, 6:47 p.m.: New moon occurs.

Sunday, 7:16 p.m.: The Sun will be 17.2 degrees above our west to west-by-northwest skyline when the moon makes contact with its lower right rim.

Sunday, 8:18:50 p.m.: Maximum contact occurs with 58 percent of the sun covered as seen from Jamestown. At this time both bodies will be just 7 degrees above the horizon, so be sure to find an elevated location without trees and buildings in the way.

Sunday, 9:09 p.m.: The sun sets for our locality minutes before the moon departs from the sun’s face.

Sunday, 9:16:37 p.m.: The eclipse ends as the moon leaves the lower left rim of the star, but by this time the sun will have set 1.8 degrees below Jamestown’s horizon.

Viewing the sun directly, especially with any optical device that concentrates its light and heat, could fry your retinas. Looking at the star through a No. 14 welder’s glass would be safe, as would any of the aluminized mylar solar glasses that you can find in the advertisement section of the magazines “Astronomy” and “Sky & Telescope.” Regular sunglasses will not work, as they still allow harmful infrared and ultraviolet light to pass through to your eyes.

You can also make a “pinhole camera” by taking a piece of cardboard, poking a pin or needle through it, and then holding it up with your back toward the sun (do not look through the pinhole at the solar disk!). If you orient it correctly, a small image of the sun (with the moon taking a chunk out of it) will be projected about three feet behind the pinhole on the ground or some other nearby surface.

The next solar eclipse, which will be total for some areas in the U.S., will take place on Aug. 21, 2017.

(Bratton is a professor of history and political science at Jamestown College)

Tags: news, eclipse