(KFVS) - On Aug. 21 a total solar eclipse will cast its shadow over Missouri, Illinois, Kentucky and Tennessee.
Have you ever wondered why the moon is just the right size to block out the sun during an eclipse?
It turns out that the sun is about 400 times the diameter of the moon. But the moon is 400 times closer than the sun.
So the math adds up making the moon the perfect size to show the sun's atmosphere during a total eclipse.
Here is a link to a NASA experiment you can do to show how size and distance match up in an eclipse.