"Earth Like Planet Found orbiting Proxima Centauri" by Al Paslow, published Sept.1, 2016; updated June 12, 2017, Mystic Sciences. Amazing detailed online article with artist illustration.
We may not even survive the microbes there.I suspect that should we find a planet with life and a Nitrogen Oxygen atmosphere in proportions like Earth - that the presence of life will make it uninhabitable by humans. Even if the essential biochemistry is very similar it seems likely there will be incompatibilities, aka poisons and allergens. Infections, infestations, predations possible as well -and I think it would be a mistake to introduce any terrestrial life on such a world. It's greatest value would be scientific - and if it were possible for humans to reach such a planet they ought to be able to survive well enough in space habitats and not require on-planet colonisation for survival.
I would go along with that. I was going to say that without an atmosphere like Earth's I would not call it Earthlike - and that Earth's atmosphere is like it is because of life. But even though an atmosphere of N2, O2 and H2O as cloud and vapor would catch attention, Earth, with life wasn't always like that. So atmospheres of various kinds, that could be explained by the presence of life - and difficult to explain without - would be the first thing to look for to find "Earthlike".No life = not earthlike. Simple.
Look, planets that were once capable of life forming in them were earthlike at that time, not at the present time. And, in case of planets which might be able to have life in the future, it will be earthlike when it has life, not now. Yes, you can say that a planet is earthlike in dimension, or earthlike in position from its parent star. But, it's not perfectly earthlike. I hope you can understand my point,I respect your opinion, but do you not agree that there should be some nomenclature to cover planets similar to Earth (in dimensions, position, etc) which had or maybe will have life, or maybe will just share some non-life characteristics? What would you call them? Or define them?
Cat, I have already told what I meant to say. My point is that, just stop saying that you have got earthlike planets, say how it is earthlike. Is it earthlike in dimensions? Is it earthlike in position from the sun? Is it earthlike in mass? Is it earthlike in terms of life? I am bored of the generalisation of the term of "earthlike." That's what my point is. To be more simple, my point is that, a planet can only be called perfectly earthlike if it matches the composition, the atmosphere, the shape, the mass of Earth and of course, it has got to have life. That is when a planet becomes perfectly earthlike, otherwise, it just remains earthlike in a specific category.IG: "But, it's not perfectly earthlike. I hope you can understand my point,"
I totally understand your point. I hope you understand mine.
I accept you could use the description "perfectly Earthlike" - you might, perhaps, consider "biologically Earthlike" as covering any life form?
You, personally, may not need them, but there may be a necessity to describe non-biological earthlike planets for whatever purpose. I think you might agree that science is best served by the best nomenclature. "The map is not the territory" but the best description, allowing for semantic obfuscation, should be in the best interests of science, and therefore in the future of humanity (if any).