Someone once complained to me that meteor showers always occur at dawn -- the most inconvenient of times; why couldn't they occur at sunset? I explained that at dawn is when your side of the planet is hurtling forward into space, as opposed to at dusk: where you're on the backside of the planet. So essentially, at dawn your sky is the windshield of the planet, and meteors are the fireflies splattering across as you drive the orbital highway. At dusk you're just Earth's butt. Earthbutt.