The best way to visualize the speed of light — 186,000 miles or 300,000 km per second — is to picture looking at the Earth from far away and seeing a ball of light spinning around the Earth 7 times per second. Now imagine that ball of light takes off from the Earth in a straight line, going the same speed. Think of how unfathomobly far away that ball of light is a year later. That’s a light year. Or, we can try this comparison: If Switzerland were a grain of sand, a light year would be the circumference of the Earth.
Still — in the grand scheme of things that is still not that much. If you travel a light year from Earth you end up in the middle of nowhere, still way closer to Earth than to anything outside the Solar System.
Keishinrei 