Olar eclipses are astounding. When the moon’s shadow moves over the earth, it can block the sun. The eclipse can be partial or t
otal. In a partial solar eclipse, the sun looks like a wheel of cheddar cheese that has a big bite missing from its side. Partial solar eclipses are more common than total solar eclipses, but both are unusual and awesome. In a total solar eclipse, the view of the sun changes more radically. The bright ball of light seems to transform into a dark black circle. Around the dark circle, there are swirls of light. The bright white light flows out from the black core, reminding some people of the head of a flower. When people see the magnificent view, they marvel. They wonder about things bigger and more powerful than themselves.
Solar eclipses are rare. Two conditions have to occur simultaneously for the sun to be eclipsed by Earth’s moon. First, there needs to be a new moon. Second, the moon’s orbit has to cross Earth’s orbit. Let’s talk about the new moon first. We say that there is a new moon when the moon moves between Earth and the sun. The new moon is sometimes called the dark moon because, from Earth’s perspective, no light is shining on it at that time. As a consequence, people on Earth can’t see it. From Earth’s perspective, there is a new moon about every 29.5 days. Now let’s talk about the second condition for a solar eclipse. Solar eclipses only happen when the moon is in line with the ecliptic, the path the sun seems to take each year. That ideal alignment does not happen very often because the moon’s orbit around Earth is 5 degrees off from the annual path of the sun. Put another way, the moon moves at an angle, and that usually prevents its shadow from falling on Earth.
Understanding shadows and solar eclipses will help us understand why some eclipses are partial and some are total. When the sun is behind the moon, the moon casts a shadow. However, because the sun, Earth, and moon are not exactly aligned, the new moon’s shadow often falls in space. But every once in a while, the moon temporarily crosses the sun’s path, the ecliptic. In that moment, the new moon’s shadow actually touches Earth, causing an eclipse. There is a partial solar eclipse when the moon is farther away from Earth. In that case, only its lighter outer shadow reaches Earth and only part of the sun is blocked. But when the moon is closer to Earth, both its light outer shadow and its dark inner shadow reach Earth. In that case, there is both a partial and a total solar eclipse. People standing in the outer shadow see a partial eclipse, and people standing in the inner shadow see a total eclipse.
If you are lucky, you may one day stand in a shadow of the moon. Then you, too, will see a spectacular solar transformation.Based on the information in the passage, what is the most likely reason why the sun’s path is called the ecliptic?
A
The sun’s path is as astounding as an eclipse.
B
Eclipses happen when the moon crosses the sun’s path.
C
Eclipses are vast, and the path of the sun is also vast.
D
The sun only moves when there is an eclipse.
