If they wanted Earth then they'd have come here long ago. I can only think of one reason why they might want to destroy us - but surely would have better options than that. And that is if we start to colonize the galaxy.
If there are ETs and they know about us - then they probably don't care what we do to this star, one of so many stars in the galaxy and the star we evolved around.
But - if we start to expand exponentially - we could transform the galaxy within a few million years - not just us - but the machines we create - amongst those hundreds of trillions of humans - just needs one to create a badly designed or thought out self replicating machine, or cyborg or new biological entity of some sort able to spread through space - and that could be hazardous to the whole galaxy as it evolves.
So they might have safeguards to prevent that - that is if they exist.
If they wanted to destroy us, an ET just a few centuries advanced over us could do it in a few minutes with self replicating nanobes so small we couldn't see them with optical microscopes, and look indistinguishable from nanobes in our electron microscopes.
They would surely have a thousands or millions of of years old civilization though - they would be ancient because chances they evolve to technology within a few thousand years of us must be tiny in the billions of years of the galaxy.
They probably individually have long lives also - maybe individuals live for thousands of years - if advanced future technology and ability to get here in spaceships.
Beings like that would not be in a hurry, and would have everything they need on a material level already supplied by their technology. They can't have a shortage of basic materials or indeed of anything material - if they did - then they'd have needed to do exponential growth expansion through the galaxy, and would be here already - millions of years ago.
So just the fact that we've been able to evolve shows that for any ETs, the Earth itself is not something they need, not technological ETs anyway - with self replicating technology it would be easy for them to find all the "Earth like" planets in the galaxy and have already done that millions of years ago - if they exist and wanted to know the answer to this question.
So - the fact that we are here, that the galaxy and our solar system is not filled with Alien ships - and that we are able to go our own way on the Earth - to my mind anyway that suggests that we have nothing to fear from them if they exist.
But - if we start to colonize the galaxy - well if there are ETs who live in the same galaxy as us, with technology millions of years ahead of us - then they'd need to do something at that stage to control what we do, for their safety - and quite possibly for our safety also.
I don't know if such ETs exist. But seems to me reasonable if they do, that they would want to keep an eye on other ETs that show signs of colonizing the galaxy and step in and do something if they do. Could just be as simple as warning them about the possible consequences if they do that - followed by more forceful methods to stop them if they persist.
While - exploring the galaxy without colonizing doesn't have those issues.
BTW them being old and technologically advanced doesn't mean they have nothing to learn from us.
They might have a lot to learn from us also. Even our maths and technology could have followed directions they never thought of.
But also - less tangible things - our youth, vigour, new ideas, enthusiasm.
Doesn't even mean they have to be particularly intelligent, they might lose their intelligence when they have machines to do everything fro them, for instance
And - either they are already - compassionate living wise creatures - if so they'd act out of those qualities - and we have nothing to be concerned about - or else - then if they are not like that - then they have things they can learn - and just possibly we might be able to help in one way or another. Whether or not they know that they need those qualities.
So - I think the first stage of any encounter would probably be, learning about each other. And that might take a fair while. And it might well go two ways - not just us learning from them.
If there are ETs and they know about us - then they probably don't care what we do to this star, one of so many stars in the galaxy and the star we evolved around.
But - if we start to expand exponentially - we could transform the galaxy within a few million years - not just us - but the machines we create - amongst those hundreds of trillions of humans - just needs one to create a badly designed or thought out self replicating machine, or cyborg or new biological entity of some sort able to spread through space - and that could be hazardous to the whole galaxy as it evolves.
So they might have safeguards to prevent that - that is if they exist.
If they wanted to destroy us, an ET just a few centuries advanced over us could do it in a few minutes with self replicating nanobes so small we couldn't see them with optical microscopes, and look indistinguishable from nanobes in our electron microscopes.
They would surely have a thousands or millions of of years old civilization though - they would be ancient because chances they evolve to technology within a few thousand years of us must be tiny in the billions of years of the galaxy.
They probably individually have long lives also - maybe individuals live for thousands of years - if advanced future technology and ability to get here in spaceships.
Beings like that would not be in a hurry, and would have everything they need on a material level already supplied by their technology. They can't have a shortage of basic materials or indeed of anything material - if they did - then they'd have needed to do exponential growth expansion through the galaxy, and would be here already - millions of years ago.
So just the fact that we've been able to evolve shows that for any ETs, the Earth itself is not something they need, not technological ETs anyway - with self replicating technology it would be easy for them to find all the "Earth like" planets in the galaxy and have already done that millions of years ago - if they exist and wanted to know the answer to this question.
So - the fact that we are here, that the galaxy and our solar system is not filled with Alien ships - and that we are able to go our own way on the Earth - to my mind anyway that suggests that we have nothing to fear from them if they exist.
But - if we start to colonize the galaxy - well if there are ETs who live in the same galaxy as us, with technology millions of years ahead of us - then they'd need to do something at that stage to control what we do, for their safety - and quite possibly for our safety also.
I don't know if such ETs exist. But seems to me reasonable if they do, that they would want to keep an eye on other ETs that show signs of colonizing the galaxy and step in and do something if they do. Could just be as simple as warning them about the possible consequences if they do that - followed by more forceful methods to stop them if they persist.
While - exploring the galaxy without colonizing doesn't have those issues.
BTW them being old and technologically advanced doesn't mean they have nothing to learn from us.
They might have a lot to learn from us also. Even our maths and technology could have followed directions they never thought of.
But also - less tangible things - our youth, vigour, new ideas, enthusiasm.
Doesn't even mean they have to be particularly intelligent, they might lose their intelligence when they have machines to do everything fro them, for instance
And - either they are already - compassionate living wise creatures - if so they'd act out of those qualities - and we have nothing to be concerned about - or else - then if they are not like that - then they have things they can learn - and just possibly we might be able to help in one way or another. Whether or not they know that they need those qualities.
So - I think the first stage of any encounter would probably be, learning about each other. And that might take a fair while. And it might well go two ways - not just us learning from them.
About the Author
Robert Walker
Writer of articles on Mars and Space issues - Software Developer of Tune Smithy, Bounce Metronome etc.Studied at Wolfson College, Oxford
Lives in Isle of Mull
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