Imagine there was no tilt to the earths axis and earths orbit was circular

If the Earth was not tilted on its axis, there would be no seasons. And humanity would suffer.

Explanation:

When a Mars-size object collided with Earth 4.5 billion years ago, it knocked off a chunk that would become the moon. It also tilted Earth sideways a bit, so that our planet now orbits the sun on a slant.

Hope this helps!

Brain-List?

colors do exist. the color of the sky is actually violet; humans percieve the color of the sky as blue.