article_snippet: On occasion, the sun, moon and Earth are perfectly aligned so that when the moon passes in front of the sun the moon casts a shadow on Earth, blocking the light.
article_snippet: A total eclipse can only be seen in the narrow corridor known as the "path of totality" --- or the "inner umbral shadow.
article_snippet: The area where the sun's rays are only partially obscured is called the "penumbra.
article_snippet: At apogee, The moon doesn't appear quite big enough to completely obscure the sun during a solar eclipse and an observer sees a ring of brilliant light around The moon.
article_snippet: This is called an annular eclipse.
article_snippet: The eclipse at totality allows us to see the inner most regions of the sun's atmosphere even if it's only for a few minutes -- it's very hard to do otherwise," Astronomer Robert Massey of the UK's Royal Astronomical Society said.
highlights_snippet: Solar eclipses happen when the sun, moon and Earth are perfectly aligned so that when the moon passes in front of the sun the moon casts a shadow on Earth .
  