Everything you need to know about Total Solar Eclipse on Apr 8th, 2024 Solar eclipse happens when moon's orbit comes in between the Earth and the Sun. But, how the moon with its small size covers the big Sun? The Sun's diameter is 400 times larger than moon's, and an interesting point is the Sun is 400 times farther from the Earth. That's how on an Annual Solar Eclipse, they both appear to be of same size in the sky.