Scientists Say: Eclipse | Science News for Students

Scientists Say: Eclipse

This is what happens when a celestial body moves into the shadow of another
Apr 24, 2017 — 6:50 am EST
solar eclipse

When the moon passes in front of the sun, the moon casts its shadow on the Earth, blocking the view of our local star. This is a type of eclipse (seen here in an illustration).


Eclipse (noun, “ee-CLIPs”)

This is when one celestial body — such as the moon or sun — moves into the shadow of another body. When the moon passes in front of the sun, it casts its shadow on the Earth. This causes a solar eclipse. During a lunar eclipse, Earth gets between the sun and the moon and casts its shadow over the moon. From Earth, the moon appears red. In a total eclipse, one object appears to be completely blocked by another. A partial eclipse leaves a part of the sun or moon visible from Earth.

In a sentence

A total solar eclipse occurs only about 75 times in every 100 years!  

lunar vs solar eclipse
A lunar eclipse (left) occurs when the Earth comes between the moon and sun, casting its shadow on the moon. A solar eclipse (right) happens when the moon moves between the Earth and sun, casting its shadow on the Earth.

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Power Words

(more about Power Words)

celestial     (in astronomy) Of or relating to the sky, or outer space.

eclipse     This occurs when two celestial bodies line up in space so that one totally or partially obscures the other. In a solar eclipse, the sun, moon and Earth line up in that order. The moon casts its shadow on the Earth. From Earth, it looks like the moon is blocking out the sun. In a lunar eclipse, the three bodies line up in a different order — sun, Earth, moon — and the Earth casts its shadow on the moon, turning the moon a deep red.

moon     The natural satellite of any planet.

planet     A celestial object that orbits a star, is big enough for gravity to have squashed it into a roundish ball and has cleared other objects out of the way in its orbital neighborhood. To accomplish the third feat, the object must be big enough to have pulled neighboring objects into the planet itself or to have slung them around the planet and off into outer space. Astronomers of the International Astronomical Union (IAU) created this three-part scientific definition of a planet in August 2006 to determine Pluto’s status. Based on that definition, IAU ruled that Pluto did not qualify. The solar system now includes eight planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

solar eclipse     An event in which the moon passes between the Earth and sun and obscures the sun, at least partially. In a total solar eclipse, the moon appears to cover the entire sun, revealing on the outer layer, the corona. If you were to view an eclipse from space, you would see the moon’s shadow traveling in a line across the surface of the Earth.

sun     The star at the center of Earth’s solar system. It’s an average size star about 26,000 light-years from the center of the Milky Way galaxy. Also a term for any sunlike star.