This means that in the far past eclipses were less dramatic as the Moon appeared larger, and that in the far furture, eclipses will be considerably less dramatic as the Moon will appear smaller (and will not, for example, be able to cover the entire disc of the Sun): we are in a unique position, both in space and time. The above coincidence is made even more remarkable by the fact that the Moon is moving away from the Earth.This is not due to any special effects of the universe it's just a remarkable coincidence. The relative sizes and distances of the Earth, Sun and Moon mean that the Earth's shadow covers the Moon almost perfectly during a total lunar eclipse, and the Moon covers the Sun almost perfectly during a solar eclipse.The diagram below may help to illustrate this (click to go to the originator's website). This is exactly what happens as the Moon orbits the Earth (or any other body orbits any other body!): The Moon is always (roughly) half-lit and half-shaded, but because of the movement of the Moon around the Earth, how much of the lit area we see changes due to our perspective. As you turn to face the torch-wielder, less and less of the ball is lit up (from your perspective) until, when you are directly facing the torchlight, the opposite side of the ball to you is lit up, and the side that's facing you is in darkness.Īs you continue you turn, now to face away from the torchlight you'll see a crescent of light appear on your ball's face, growing until, as you face away from the light, the entire face of the ball is lit once more. When you're facing in the opposite direction to your mate with the torch, you should see that the part of the ball that's facing you is lit up entirely*.Īs you turn slowly on the spot, you should see a crescent of shadow creeping around the part of the ball that's facing you, so that less of the visible surface of the ball is directly lit by the light from your mate's torch. With the football still held out at arm's length, slowly turn on the spot, keeping your eye on the surface of the ball in front of you. Now imagine a mate of yours is on the other side of the room holding a torch, and they're shining it at you. Imagine standing in a darkened room with a football held out in front of you at arm's length. In the following section I'll ask you to 'imagine', but there's no real reason why you can't actually do the things I'm asking you to imagine if it would help to see what's going on.

Solar vs lunar eclipse diagram