Having Trouble With This Concept

This post is not about yarn diets. Don't worry. I'm actually having some trouble with an actual scientific concept. Stay with me here.

So, you know how it takes light a certain amount of time to travel from one point to another, right? So, when we look at a planet that is 2 million light years away--the distance light can travel in 2 million years--we are not looking at that planet now. We are looking at it 2 million years in the past.

So let's think how much Earth has changed in 2 million years. Here's a hint. Modern Humans did not exist 2 million years ago.

So, for the sake of argument, let's say we use a super-duper powerful telescope to look at this planet (looking at the planet as it was 2 million years ago) and we don't see any sign of intelligent, human-like life. No buildings, cities, etc. I would argue, by the way, that a sense of humor was the best indicator of intelligence, but it's a little hard to see that, even though a super-duper powerful telescope.

BUT 2 million years have passed since what we are seeing actually occured. So that planet could actually have thriving space-faring civilizations on it now. Right? And it would be another 2 million years before we would know.

And now, they might be looking back on us. Maybe they are more advanced than we are and they are looking for promising species to welcome into the United Federation of Planets. (Just sayin'.)

Or maybe they've run out of all their cattle animals on their world and they're looking for food. (Seems like a long way to go for a human cheeseburger, but the idea seems to pop up in a lot of literature and movies, so I felt I had to, at least, acknowledge it.)

Maybe they're suffering global warming, or depleted resources, or there is some other looming catastrophe that they can see, but we can't because we can only look 2 million years into the past. Maybe they're looking for a place to colonize and they look at Earth and think, "Oh there's no intelligent life there. We won't be hurting anyone there. Let's go there."

So they send a bunch of colony ships here to live. But meanwhile, we have global warming and depleted resources and, if the Discovery Channel is to be believed, it is only a matter of time before some planet-killing asteroid hits us.

So what if we jump in our ships and move to their planet (which is about to be blown up by an asteroid) and, at the same time, they come to Earth to live, not realizing it's about to be blown up by an asteroid? And then, we've travelled so far, for so long that we can hardly even be called human any more, only to suffer the same fate as those on Earth 2 million years ago.

But wait, there's more. 

As we approached the planet, and they approached ours, time would be different. That is, since they would be physically closer, they would also be looking not quite so far into the past. Halfway there, we would see the planet not as it was when we left, and yet not as it is at that moment. We might even see, depending on the event and how far we've travelled, the asteroid hitting the planet.

It's hard to think in those terms. I think I'll go lie down.