We have heard so much about the solar eclipse that will occur in Idaho next August. The news article we read talked about the path of totality. What does that mean?

Question Answered by Dr. Brian Tonks, Astronomy Professor, BYU-Idaho

On 21 August, 2016, Southeastern Idaho and many other places in the United States are in for a rare treat. We will experience a total Solar eclipse. This means that the Moon will pass directly in front of the Sun and cast its shadow on the ground. It will be an event to behold! I’ve never personally seen a total solar eclipse, but those who have tell me it is spectacular—the sky grows dark, stars appear, but the horizon is still lieclipse1ght. The solar corona, the Sun’s outermost layer that is normally invisible, appears (see Figure 1). Many people describe it as having something like a spiritual experience.

We live in an area (and the eclipse occurs at a time) where the Moon will completely block the Sun’s visible “surface” (called the photosphere). In our area, you can see total eclipse from just south of Shelley to just north of Ashton. The center of the eclipse cuts across US Highway 20 at about Thornton. The closer you are to the center of the eclipse, the longer the total phase lasts. At the center point in Thornton, totality last a
bout 2 minutes, 18 seconds. At the edges of the totality zone, the eclipse lasts for only a few seconds. Being close to the center of totality will enhance your experience.

Because the Earth is rotating, the Moon’s shadow moves across the ground, creating a “path of totality”. Figure 2 is a map from NASA’s web site about the eclipse (http://eclipse.gsfc.nasa.gov/SEgoogle/SEgoogle2001/SE2017Aug21Tgoogle.html). The path of totality begins in the Pacific Ocean and strikes land along the northern Oregon coast. The blue lines represent the northern and southern-most extent of totality; the magenta line represents the center of totality. As you can see, the eclipse crosses the entire country. Those of us who live from Idaho Falls to Ashton are in a prime location to experience the total eclipse.

Next week: Where and When to View the Eclipse

Make an Edible Sun Model

The Sun is a dynamic and active star. If you look at it with a telescope, pin-hole camera or special eclipse glasses, you can see features on the sun that are moving and changing. (Remember you should never look directly at the sun!)
Materials: round plain cookies, white frosting, yellow and red sprinkles, chocolate chips or mini M&M’s, pull-n-peel licorice candy, knife, paper plateeclipse3

  1. Spread white icing all over your cookie.
  2. Shake some yellow and red sprinkles on the frosting. These form the granular appearance of the photosphere.
  3. Place a few chocolate chips on the cookie to represent sunspots. Sunspots appear in pairs, so put two chips close to each other.
  4. Separate the licorice and cut it into small pieces. Place a few pieces of licorice on the cookie, forming small arches. Hot, glowing plasma flows between sunspots creating a solar prominence. They are generally found near sunspots where the area is active and has a stronger magnetic field.

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