The speed of light is 186,000 miles per second. That’s per second, not per hour. If you travel at the speed of light for an hour, you cover 671 million miles.
That’s fast, right?
Well maybe on Earth it is, but the universe is a big place. It took about five hours for the signal from the New Horizons probe to travel from Pluto to Earth. And that’s traveling at the speed of light.
To put it in perspective, take a look at this if you’ve got 45 minutes to spare:
That’s how long it would take to get from the Sun to Jupiter: 45 minutes.
Forty-five minutes of nothing but emptiness with a few big space rocks called planets, moons and asteroids showing up every few minutes to break up the monotony. I bore easily, so if it took this long to get to Jupiter, imagine how many “Are we there yet”s I’m going to ask on a trip to Pluto.
If we’re ever going to get to other parts of the galaxy, we’re going to have to break the light barrier. Which means we’re probably not going anywhere. Maybe a billion years from now, our robot satellites in space like Pioneer, Voyager and New Horizons will be picked up by some alien civilization, which will ask: What the hell is this?
This is the Golden Record we sent on Voyager back in 1977: a collection of greetings in different languages, sounds of life and selections of music, plus a roadmap to where we are. Voyager has left the solar system and is now in interstellar space.
So let’s say Voyager does end up on a planet in another part of the galaxy where there’s intelligent life. What do you think the aliens would say? Maybe this?
Check out the Speaking of Science blog at the Washington Post for more about the Golden Record.