This is a real-time visualization of light traveling from Earth to Mars, and back again. Each direction takes 3 minutes and 2 seconds at a close approach distance of 54.6 million kilometers (~33.9 million miles), for a total speed-of-light roundtrip of 6 minutes and 4 seconds. That means if I mooned the aliens on Mars right this second, the light reflecting off my near-perfect ass cheeks wouldn't reach them for 3 minutes and 2 seconds, at which time, universe willing, they'd be so outraged they'd mash the big red button on their speed-of-light superlaser, and another 3 minutes and 2 seconds later Earth's pesky human problem would be solved. "Pull your pants back up already." Shhhhhhh -- just in case they weren't watching right away.
Keep going for this video, as well as BONUS videos of the speed of light traveling around earth, and to the moon and back.
Thanks to Adam W, who informed me he loves space as much as I do, which is a lie because I am space lover numero uno and have the official paperwork for all the stars I adopted as a kid to prove it.