Yes, why would they? And would we notice it?
There are a lot of movies and other media about what would happen if aliens came to this planet, Earth.
Mostly, they show them as aggressive and brutal invaders, coming here to take over and destroy humans so they can use the planet for themselves.
We humans, so far, have not the possibility to leave this planet and go on such "long" (meaning the distance AND the time) journeys. We are technically not advanced enough for that.
So, any visitor from "outer space" would be much more advanced in technology and the actual use of it than we are right now. Even so, it would take a lot of "money" (if they still use money) or some other kind of "payment"; i.e. the alien labour put into it as well as all the resources needed to complete the project.
And I don't think it can be done by a few alone. So, different to our planet, the aliens already would (have to) be all unified - one gigantic civilisation - all working on achieving the goal.
I'll leave aside all the technical and scientific explorations of the "if it is possible" that there are alien worlds at all, if they are advanced enough, will have enough resources and the actual possibility of space travel in such a physical way. And assume that they can do it.
Now, you may ask: "Why would they want to come to a planet like ours? We humans are so much "below" them in technology (and in many other things too)! There simply is nothing (of interest - as if we would know what interests them, hahaha) they could get from us - except the planet itself. It is our home and we will defend it!" And if you like to believe in the reality that movies show you, we will chase them off again. Hooray!!
If you are more realistic, then I think, to assume they will just take what they need and don't bother about killing off a few billion of possible intelligent lifeforms, is not too way off.
If you assume that the aliens think and behave like we do!
BUT
I think, that there is a big chance that aliens are very different from us. More advanced and evolved in many things - not only technology.
So, if they would go out on such a thing to look for other inhabited planets like ours, then surely not because they want it "just for themselves".
You might say: "What if their own planet and sun are dying and they just NEED to go some other place?"
Even in that case, I think, they wouldn't take over a planet that already has "intelligent" life on it; or life that is still evolving and becoming "intelligent". There are so many other planets that they easily, with all their technology, could make habitable. Planets that have all the resources that are needed and, with a little help, will support their life.
Anyway, our planet will have to be made habitable for them too; not all of it will be perfect (and as polluted as our planet is by now, it is not perfect for us too - but that's another story!) And then rid it of part of it's life first? That's way too much of an effort and not "economic" even for an advanced civilisation.
And, how would the aliens know if that life-form they are about to destroy so they have solely access to the planet is not an important part of that planet's life?
(Yes, the planet as such has a life too - the "non-animated" forms like rocks are alive too.
"The trans-disciplinary theory demonstrates that purportedly inanimate, non-living objects -- for example, planets, water, proteins, and DNA -- are animate, that is, alive."
Case Western Reserve University (2012, January 26). Radical theory explains the origin, evolution, and nature of life, challenges conventional wisdom. ScienceDaily. Retrieved January 28, 2012, from http://www.sciencedaily.com/releases/2012/01/120126115127.htm# read at link for more on the theory. )
Our scientists study lifeforms, the ecosystems and how they interact. And through publishing their findings and educating others around them, slowly we all understand that there is more to "life on a planet" then just us as the "highest" evolved life-form.
Example: Scientist study ants. You may ask: "What for? They are so below us in the "evolution"! What can ants show us that we don't already know?" A lot, I say! (And the scientists.) About how community works, about how to handle resources, about how to live WITH nature (and the planet) and not against it. Ants (as an example - there are many more) just KNOW how to do all that. They don't have technology - but they live all over the planet (more numerous than humans in fact). Maybe they are the true "intelligent" life-form of this planet?
So, I think, aliens would, coming across a planet like ours, surely first study it, and then either avoid it - or if they find it interesting enough - "beam" down to study it closer.
Now, you may remind me of movies like V (2009 TV series). There the aliens came to Earth to use the humans as breeding stock; in similar movies and stories humans are simply used as food. In my opinion to actually show themselves as visitors is not logical in these cases. It would be simpler and more efficient to just breed and use the humans without them knowing about it. Or would you tell the cows, pigs and sheep we use as food that you are going to eat them and then expect them to humbly succumb into it? Better not let them know. Quick and fast - no "visiting".
On a side note: do you think such very advanced aliens and humans have an equal basis for communication? I don't mean the different language or way of speaking, but the one of the "advanced" being to "not-as-advanced" being. Or do you think ants really understand you when you talk to them? These are just some thoughts that show how difficult an encounter with aliens could be.
Another option for "visitng" humans, you might want to add, is that they use humans as workers/slaves. Well, that's a thing that I opt out rather fast. If those aliens are so advanced to us that they can travel all the way here in reasonable time, they also have the means to built "robots" and such devices to do the work for them. They wouldn't use "weak" humans for that. Even we humans use "stronger" animals to do work for us because those are better suited for the task.
"They come to "feed" on our emotions!" Well, that's another possible reason to come here - but not one to actually visit in a way so that we notice them, is it?
So, let's assume the aliens come as visitors after having studied us humans for some time. And have solved all the difficulties of how to interact with "not-as-advanced" beings as themselves. Knowing how "fearful" humans are of strangers they sure would do that in a way to go "unnoticed"; appearing and acting like any other human here does too. We wouldn't notice them; unless they want to be noticed. Once their studies are completed, it's a stay-or-go decision.
Then again, maybe they don't come to visit us. They come to visit the planet. As they care about the planet, its life! And want to "heal" it from the lifeforms that make it "sick". In this case it is very possible they would get rid of the humans as the most sick-making factor. Or teach them (us humans) to heal the planet by themselves; so that we can go on living with it.
Maybe this "teaching" is already happening. Why would they - the aliens - do such a thing? Maybe because they care (more than we so far) about the planet and maybe had to go through similar events to evolve to the kind of civilisation they are now. And they feel that it is their "duty" and responsibility to help.
Or, they are still thinking of a good way to get rid of the humans without "hurting" the planet further. In this case, I think, we wouldn't notice that they are dong it. Not like in the movies. With their so much more advanced technology there would be a way to do it in seconds.
So actually, after all this, to meet an alien face-to-face (and recognise it for what it truly is) has only a tiny chance.
But, maybe no aliens have been here yet. And we have to do the clean-up and evolving all on our own. Because, if the aliens don't come to us - maybe one day we are ready to go and visit them.
And where would we go? Well, our scientists are searching a lot. For example with the Kepler telescope. Recently they found 11 new "planetary systems". ( Kepler telescope finds 11 new solar systems )
We are still at the beginnings of this. Still have to find out which planets are in a habitable zone that could support life like ours (so that we can actually interact with it). And we still have to find a means to bridge the vast distances.Mostly, they show them as aggressive and brutal invaders, coming here to take over and destroy humans so they can use the planet for themselves.
We humans, so far, have not the possibility to leave this planet and go on such "long" (meaning the distance AND the time) journeys. We are technically not advanced enough for that.
So, any visitor from "outer space" would be much more advanced in technology and the actual use of it than we are right now. Even so, it would take a lot of "money" (if they still use money) or some other kind of "payment"; i.e. the alien labour put into it as well as all the resources needed to complete the project.
And I don't think it can be done by a few alone. So, different to our planet, the aliens already would (have to) be all unified - one gigantic civilisation - all working on achieving the goal.
I'll leave aside all the technical and scientific explorations of the "if it is possible" that there are alien worlds at all, if they are advanced enough, will have enough resources and the actual possibility of space travel in such a physical way. And assume that they can do it.
Now, you may ask: "Why would they want to come to a planet like ours? We humans are so much "below" them in technology (and in many other things too)! There simply is nothing (of interest - as if we would know what interests them, hahaha) they could get from us - except the planet itself. It is our home and we will defend it!" And if you like to believe in the reality that movies show you, we will chase them off again. Hooray!!
If you are more realistic, then I think, to assume they will just take what they need and don't bother about killing off a few billion of possible intelligent lifeforms, is not too way off.
If you assume that the aliens think and behave like we do!
BUT
I think, that there is a big chance that aliens are very different from us. More advanced and evolved in many things - not only technology.
So, if they would go out on such a thing to look for other inhabited planets like ours, then surely not because they want it "just for themselves".
You might say: "What if their own planet and sun are dying and they just NEED to go some other place?"
Even in that case, I think, they wouldn't take over a planet that already has "intelligent" life on it; or life that is still evolving and becoming "intelligent". There are so many other planets that they easily, with all their technology, could make habitable. Planets that have all the resources that are needed and, with a little help, will support their life.
Anyway, our planet will have to be made habitable for them too; not all of it will be perfect (and as polluted as our planet is by now, it is not perfect for us too - but that's another story!) And then rid it of part of it's life first? That's way too much of an effort and not "economic" even for an advanced civilisation.
And, how would the aliens know if that life-form they are about to destroy so they have solely access to the planet is not an important part of that planet's life?
(Yes, the planet as such has a life too - the "non-animated" forms like rocks are alive too.
"The trans-disciplinary theory demonstrates that purportedly inanimate, non-living objects -- for example, planets, water, proteins, and DNA -- are animate, that is, alive."
Case Western Reserve University (2012, January 26). Radical theory explains the origin, evolution, and nature of life, challenges conventional wisdom. ScienceDaily. Retrieved January 28, 2012, from http://www.sciencedaily.com/releases/2012/01/120126115127.htm# read at link for more on the theory. )
Our scientists study lifeforms, the ecosystems and how they interact. And through publishing their findings and educating others around them, slowly we all understand that there is more to "life on a planet" then just us as the "highest" evolved life-form.
Example: Scientist study ants. You may ask: "What for? They are so below us in the "evolution"! What can ants show us that we don't already know?" A lot, I say! (And the scientists.) About how community works, about how to handle resources, about how to live WITH nature (and the planet) and not against it. Ants (as an example - there are many more) just KNOW how to do all that. They don't have technology - but they live all over the planet (more numerous than humans in fact). Maybe they are the true "intelligent" life-form of this planet?
So, I think, aliens would, coming across a planet like ours, surely first study it, and then either avoid it - or if they find it interesting enough - "beam" down to study it closer.
Now, you may remind me of movies like V (2009 TV series). There the aliens came to Earth to use the humans as breeding stock; in similar movies and stories humans are simply used as food. In my opinion to actually show themselves as visitors is not logical in these cases. It would be simpler and more efficient to just breed and use the humans without them knowing about it. Or would you tell the cows, pigs and sheep we use as food that you are going to eat them and then expect them to humbly succumb into it? Better not let them know. Quick and fast - no "visiting".
On a side note: do you think such very advanced aliens and humans have an equal basis for communication? I don't mean the different language or way of speaking, but the one of the "advanced" being to "not-as-advanced" being. Or do you think ants really understand you when you talk to them? These are just some thoughts that show how difficult an encounter with aliens could be.
Another option for "visitng" humans, you might want to add, is that they use humans as workers/slaves. Well, that's a thing that I opt out rather fast. If those aliens are so advanced to us that they can travel all the way here in reasonable time, they also have the means to built "robots" and such devices to do the work for them. They wouldn't use "weak" humans for that. Even we humans use "stronger" animals to do work for us because those are better suited for the task.
"They come to "feed" on our emotions!" Well, that's another possible reason to come here - but not one to actually visit in a way so that we notice them, is it?
So, let's assume the aliens come as visitors after having studied us humans for some time. And have solved all the difficulties of how to interact with "not-as-advanced" beings as themselves. Knowing how "fearful" humans are of strangers they sure would do that in a way to go "unnoticed"; appearing and acting like any other human here does too. We wouldn't notice them; unless they want to be noticed. Once their studies are completed, it's a stay-or-go decision.
Then again, maybe they don't come to visit us. They come to visit the planet. As they care about the planet, its life! And want to "heal" it from the lifeforms that make it "sick". In this case it is very possible they would get rid of the humans as the most sick-making factor. Or teach them (us humans) to heal the planet by themselves; so that we can go on living with it.
Maybe this "teaching" is already happening. Why would they - the aliens - do such a thing? Maybe because they care (more than we so far) about the planet and maybe had to go through similar events to evolve to the kind of civilisation they are now. And they feel that it is their "duty" and responsibility to help.
Or, they are still thinking of a good way to get rid of the humans without "hurting" the planet further. In this case, I think, we wouldn't notice that they are dong it. Not like in the movies. With their so much more advanced technology there would be a way to do it in seconds.
So actually, after all this, to meet an alien face-to-face (and recognise it for what it truly is) has only a tiny chance.
But, maybe no aliens have been here yet. And we have to do the clean-up and evolving all on our own. Because, if the aliens don't come to us - maybe one day we are ready to go and visit them.
And where would we go? Well, our scientists are searching a lot. For example with the Kepler telescope. Recently they found 11 new "planetary systems". ( Kepler telescope finds 11 new solar systems )
And before actually visiting those planets: do our "homework" here and evolve in many, many fields to become that sort of advanced civilisation that could and would be the "visiting" aliens!
And after all -- these arguments are just my thoughts on why aliens would come for a visit. But who knows why they would (or would not) do it truly. Maybe one day, I meet an alien and can ask it about the why (and how). ^^
