Solar Eclipses

    Solar eclipses are, perhaps the most entertaining spectacle in the sky. There is a great number of people who regularly spend a great deal of money to chase these types of eclipses. An eclipse site can become quite a tourist destination.

    One must be in the right place at the right time in order to see a total solar eclipse.Only if you arrange to find yourself in the umbra of the Moon's shadow will you get a chance to see this show. Those observers who are merely in the penumbra of the Moon's shadow will only see a partial solar eclipse. Hardly worth the trouble of going outside to take a look.

And on the matter of looking at a solar eclipse, the rules are very straightforward.

Never look at the photosphere of the Sun!

Okay, what does that mean?

Well the photosphere is the bright part of the Sun where all the light comes from. Good name, eh? In any partial eclipse, there is a pretty big part of the photosphere still showing. Even seconds before totally occurs, with perhaps only a thousandth of the photosphere showing, you could still damage your eyes. Then why does the media give us those urgent warnings on the day of an eclipse? On any other day, it does not occur to most of us to stare at the Sun. That would be very dangerous and foolish, either on the day of an eclipse or any other day.

  But if by design or happy accident, you find yourself in the path of the shadow of the Moon, then by all means, enjoy the show, as long as you follow these precautions.

Here's what happens during totality:

The sky becomes dark enough for the brighter stars to come out. All around you, on the horizon, you see the orange glow of Earth's atmosphere, hundreds of kilometers away, still lit by the Sun. It looks as if the Sun has set in all directions at once. With your own eyes, you can see, at least, the inner corona of the Sun, shining like a crown surrounding the dark circle of the Moon. Depending on the amount of solar activity, the corona might stretch out quite a distance in the two directions along the equator of the Sun.

  You will notice a decided chill in the air. At the solar eclipse in eastern Montana in February of 1979, the air temperature decreased by 10 degrees Celsius in the hour or so leading up to the time of totality. Animals will act as if night has fallen. Bats fly out of caves, chickens come home to roost, dogs are definitely confused. Here is how that eclipse sounded.

    For those of you who live in the United States, here is the eclipse that you won't want to miss. The Moon's shadow will cut across the U.S. in late August of 2017. This movie shows what the eclipse would look like from several thousand kilometers out in space.
Here are other sites which give more information about solar eclipses:

Here is a map of all of the solar eclipses for the next twenty years or so. Notice the two total solar eclipses that pass across the United States.

Solar Eclipses of This Decade  Sky and Telescope Magazine
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Updated October 6, 2009