Solar Eclipse

A solar eclipse is when the moon passes between the Earth and the sun, its shadow blotting out the sun.

About twice a year, at a time when there is a new moon, part of the moon's shadow falls on the Earth's surface and there is an eclipse of the sun seen in some place on Earth. Most of the time, the moon's shadow misses Earth at new moon because the moon's orbit is tilted at 5º to Earth's orbit around the sun.

The moon has no light of its own, but shines because sunlight is reflected off its surface. It orbits (circles around) the Earth, and each orbit takes twenty nine and a half days.

When we see the moon from Earth, its changing position as it orbits makes it look different. This is called the 'phases of the moon'. The phases are:
1) new moon, 2) new crescent, 3) first quarter, 4) waxing gibbous, 5) full moon, 6) waning gibbous, 7) last quarter, 8) old crescent, then back to new moon again.

New moon cannot actually be seen because the shining side of the moon is facing away from Earth, and the dark side is facing Earth. The new moon is close to the sun in the sky as we look at it from Earth, so it rises and sets at the same time.

The moon's shadow has two parts:
Penumbra: a faint outer shadow
Umbra: a dark inner shadow

When just the Penumbra shadow touches Earth, it is a partial eclipse of the sun in that place. Only part of the sun is blocked. The part of the sun not eclipsed is very bright, and it is very harmful to the eyes to look at it without special filters.

When the Umbra shadow touches Earth, a total eclipse of the sun is seen in that part of the world. The time that the sun is completely blocked out in a total eclipse takes just a few minutes, but is a spectacular sight. Day becomes twilight as the black shadow of the moon completely blocks the sun, but a halo effect surrounds it, caused by the sun's corona.

The Path of Totality is the section of Earth that can see a total eclipse. This is in different parts of the world each time.

Did you know? People in ancient Egypt, Asia and Greece worshipped the sun. They thought that an eclipse of the sun, when the moon passes in front of the sun and blocks the light, was the sun god showing anger.

Go to http://www.kidseclipse.com/ to find out more about solar eclipses. Click on 'Teach' and scroll down the page, click on questions at the bottom of each page

http://colorsofindia.com/eclipse/whatowatch.htm tells you about the stages of a total eclipse

Go to http://www.assa.org.au/observing/eclipse2002/ If you use any part of this, acknowledge it in your bibliography like this:
 Sydenham & Thomas, Solar Eclipse. [Online] www.kidcyber.com.au (2008)

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Updated June 2008