Earth and the Moon


What is an annular solar eclipse?

Since the Moon travels in a slightly elliptical orbit around Earth, rather than in a perfectly circular path, its distance from Earth is not always the same. If the Moon’s umbra falls on Earth’s surface when the two bodies are at a closer point in the Moon’s orbit, the solar eclipse is total there. But if the Moon happens to be too far away from Earth at that time, the Moon does not cover enough of the sky to block the Sun’s rays entirely. In that case, the Sun is seen as a ring, or annulus, of light glowing around the silhouette of the Moon.


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