I don’t want to move to Mars. It’s a very dangerous environment, you’d be indoors all the time or else wearing a spacesuit for short adventures outdoors. I don’t even think it’s advantageous for humans to go to Mars at all when we could just as well, and for much less expense, send our probes and robot rovers there instead. There is no good scientific reason to go to Mars.
People will go, however, because not everyone is scientifically minded.
During Earth’s night you can see the lights of major cities from the moon. So this would imply that further out from the moon one could detect light. Then there are the radio and television waves. They go out infinitely into space, but they become four times weaker every time the distance doubles. In any case, we pick up radio signals from Voyager I and II even though they have left the solar system, so I would suppose people could pick up our radio signals quite far away.
Just as soon as we can solve the problem of only going 20 times slower than 1 tenth the speed of light, our fastest speed to date. Sadly, the ability for humans to send humans to other stars will most likely never happen.
We have already commercialized space travel. Private companies are now being paid to resupply the International Space Station on a regular basis, and commercial companies are hiring SpaceX, another commercial company, to place satellites into orbit.
Well, let’s not put the cart before the horse. Right now we don’t know for sure that any life exists anywhere other than Earth. We suppose it does by mathematical calculations, but we haven’t even found a fossil of a microbe from space.
Secondly, suppose there is some super advanced civilization (your use of “exponentially” doesn’t seem to make any sense), the reason they probably haven’t completely colonized the entire Milky Way Galaxy is that for them, as for us, the laws of physics make it pretty much impossible to achieve interstellar travel because of the vast distances involved. And even if they could colonize some surrounding systems by now, it would take light and radio waves 100,000 years to reach us from the other side of the galaxy.
It already is being used for military purposes right now as in spy satellites. Even very recently SpaceX was tasked to launch a U.S. spy satellite into orbit but it exploded and the satellite didn’t make it.
In 1984 a Titan 34D rocket launched the KH-9 and KH-11 satellites for “reconnaissance,” and the DSP-2-6R satellite for missile detection. The list just starts there and goes into the hundreds including many intelligence-gatheringsatellites and so on.
And, by the way, not just by the United States, but other governments as well.
Furthermore, the Chinese government once shot a missile to destroy their own satellite in space just to say the could, and they succeeded, vastly increasing the dangerous debris cloud floating now in orbit. It was a military demonstration.
Mechanical, intentional interstellar travel is unlikely since the distances are far too great to imagine. The best anyone could achieve is interplanetary travel within one’s own solar system. Therefore, if we pass the buck and say life didn’t start here but started somewhere else and arrived here, it would have had to arrive on a rock or asteroid as a microbe and somehow survive a fiery entry through Earth’s atmosphere and it would have had to survive the vacuum and temperature extremes of space. If the rock came from outside the solar system it would have had to survive a long, long time.