On rare occasions,
when the Moon passes between the Sun and Earth, its shadow will fall on part of the Earth’s
surface. This shadow is what we call a solar eclipse. Solar
happen during a NEW MOON!
Think about how on a cloudy summer day, as a cloud
passes between you and the Sun, it will get a little darker, in its shadow. This is EXACTLY
what happens during a solar eclipse, only it is the Moon’s shadow instead of a cloud.
Solar Eclipses are MUCH more rare than lunar eclipses. They are rare because the Moon is so small
that it casts a very small shadow onto the Earth and you must be directly under the shadow to see the
eclipse. The next total solar eclipse that will be visible in North America won’t occur until
August 21, 2017, whereas, the next lunar eclipse that we could see part of is in December.
We know that the Moon orbits the Earth every month, so why don’t we have an eclipse every
month? The answer is simple, those elliptical orbits! Remember, the Earth’s orbit
is elliptical around the Sun and the Moon’s orbit is elliptical around the Earth. Those
elliptical orbits have to match up just right to cause an eclipse.
Which is more
common, a lunar eclipse or a solar eclipse?