Solar eclipses are some of nature’s most dramatic celestial performances. Solar eclipses occur when the Earth, moon and sun are aligned in the same plane and the moon passes between the Earth and the sun, partially or completely covering our closest star. The next solar eclipse will occur on March 9, 2016 — learn more on that below.
There are four types of solar eclipses: total, annular, partial and hybrid. Here’s what causes each type:
Total solar eclipses
These are a happy accident of nature. The sun’s 864,000-mile diameter is fully 400 times greater than that of Earth’s moon, which measures just about 2,160 miles. But the moon also happens to be about 400 times closer to Earth than the sun (the ratio varies as both orbits are elliptical), and as a result, when the orbital planes intersect and the distances align favorably, the new moon can appear to completely blot out the disk of the sun. On the average a total eclipse occurs somewhere on Earth about every 18 months