Solar Eclipse
Listen now
Transcript: Solar eclipses are among the most spectacular phenomena that can occur in the sky. During a solar eclipse, the Earth darkens substantially during broad daylight; the temperature can drop 5 or 10 degrees. A solar eclipse occurs when the Moon passes between the Earth and the Sun, and the Moon casts its shadow on the Earth. Because the Moon shadow is much smaller than the Earth’s shadow, solar eclipses are much rarer than lunar eclipses. During a solar eclipse, the point or full shadow of the Moon, the umbra, casts darkness on the Earth’s surface. A larger annular region around the umbra called the penumbra has partial shadow. Because the Earth is rotating during a solar eclipse, the shadow tracks across the Earth’s surface at speeds approaching 1000 miles per hour. Therefore, as seen from any point on the Earth’s surface, solar eclipses last only a few minutes, at most, 6 or 7 minutes.
More Episodes
Transcript: In the year 584 B.C., on the coast of Asia Minor, two warlike tribes were engaged in a fierce battle: the Medes and the Lydains. As written by the Greek poets, these two cultures were hacking away at each other on the battlefield with burnished swords and shields, when suddenly the...
Published 07/12/11
Transcript: Thales was a philosopher who lived in the 6th century B.C. in Miletus, in what is now Turkey. No written work by Thales survives, but we know that he kept accurate eclipse records and he speculated about astronomy. He decided that the source of all things was one thing, and that...
Published 07/12/11
Transcript: The apparent motions of the stars in the night sky depend on your position on the Earth’s surface. At a northern temperate latitude, the stars rise in the east and set in the west, and they travel on slanting paths across the sky. The north celestial pole sits in the northern sky...
Published 07/12/11