04 Lunar Eclipse

Lunar eclipses happen when the Moon passes through the shadow of the Earth. Du ring this kind of eclipse, the Moon appears to be a reddish colour. This can only happen during a full moon.

Some lunar eclipses can last up to 3 hours and 45 minutes and there are usually no more than three in a year. There are three main types of lunar eclipse: partial, full, and prenumbral. During a partial eclipse, only part of the Moon passes through the Earth's shadow. A full lunar eclipse occurs when the Earth passes directly in front of a full moon. When the Moon passes through the prenumbral shadow of the Earth, a prenumbral eclipse has happened.

The appearance of the Moon can vary a lot during a total lunar eclipse, due to variations in the Earth's atmosphere. The Danjon Scale is used to describe how light or dark the Moon appears during a total eclipse. The Danjon Scale has five points, ranging from 0 (almost invisible) to 5 (very bright yellowish orange). It is not dangerous to look at the Moon during a lunar eclipse, because it is not giving off its own light. More people are able to view a lunar eclipse than a solar eclipse. In ancient times, many people believed that a lunar eclipse or the disappearance of the Moon meant that the Gods were angry.

Word List

eclipse : when one celestial body passes in front of another

prenumbral : an imperfect shadow

You Practice

I. Answer the following questions.

1) What is the difference between a lunar eclipse and a solar eclipse?

2) Why is it dangerous to look directly at the Sun, but not the Moon?

3) Why do you think more people can view a lunar eclipse than a solar eclipse?

4) Have you ever seen an eclipse? If so, describe what happened. If not, would you like to?

5) How could the Danjon Scale be useful for people?

II. Word power—Use these words from the reading in sentences of your own.

1) eclipse_______________________________________________

2) solar_________________________________________________

3) lunar_________________________________________________

4) celestial______________________________________________

5) invisible______________________________________________

III. True / False / Not Given—Write T if the sentence is true, F if the sentence is not true, or NG if there is no information about the sentence.

____ 1) Lunar and solar eclipses are very common.

____ 2) Solar eclipses are more dangerous than lunar eclipses.

____ 3) There is a lunar eclipse about once a month.

____ 4) All lunar eclipses look the same.

____ 5) Lunar eclipses only happen when there is a full moon.