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View Full Version : What is the next earth?



joicegiz
2012-Dec-15, 07:55 AM
NASA says that there will be a new found earth. It's just like our earth and people can survive there. Is this true?

Van Rijn
2012-Dec-15, 10:37 PM
NASA says that there will be a new found earth. It's just like our earth and people can survive there. Is this true?

Do you have a reference for that? I doubt NASA officials would make such a claim. You might have misunderstood, or perhaps you read an article where the author made an incorrect claim about NASA. Astronomers expect to find more exoplanets with some similarities to Earth, but whether we would ever find another planet we could survive on without modification or enclosed habitats is unknown.

TooMany
2012-Dec-15, 10:48 PM
But with some knowledge (perhaps not enough yet) of the distribution of planetary systems and probabilities of Earth-like settings, it may become reasonable to say with some confidence how many earth-like planets are likely to exist among the 100 billion stars in the galaxy. I don't think we are all that far from being able to do this. Maybe a few decades.

Jeff Root
2012-Dec-15, 10:58 PM
I saw a headline a day or two ago which said that. I didn't
bother to read the article because the headline was so obviously
off-kilter. I probably should have read it anyway.

In order for humans to be able to live on another planet without
spacesuits, it would have to have life on it fairly similar to life
on Earth, because living things made Earth's atmosphere. Such
life would probably have all sorts of nasty effects on humans,
like severe allergies. Humans have developed to tolerate most
of the range of biochemicals we come in contact with, and would
not likely be able to cope with a whole new range at once. So I
think the chances of any other planets being both very Earthlike
*and* human-safe are very small.

-- Jeff, in Minneapolis

TooMany
2012-Dec-16, 12:12 AM
I see, I kind of glossed over the "humans can live there" part. I think Jeff is probably right. Even if the life forms are similar and the atmosphere has oxygen and nitrogen etc, there is the possibility that the living things or organic molecules could cause sickness or even be deadly for us. It would be a big surprise if everything was just fine and you could go around eating the plants and animals. If we want another earth, we might need to terraform some suitable planet.

There was some old science fiction story I read in which the space travelers arrive at another planet which is just like Earth until they try to eat something and find out the organic molecules are the wrong isomers, right-handed instead of left-handed. Eating is a no-go.

Achilleus
2012-Dec-16, 02:42 AM
I see, I kind of glossed over the "humans can live there" part. I think Jeff is probably right. Even if the life forms are similar and the atmosphere has oxygen and nitrogen etc, there is the possibility that the living things or organic molecules could cause sickness or even be deadly for us. It would be a big surprise if everything was just fine and you could go around eating the plants and animals. If we want another earth, we might need to terraform some suitable planet.

There was some old science fiction story I read in which the space travelers arrive at another planet which is just like Earth until they try to eat something and find out the organic molecules are the wrong isomers, right-handed instead of left-handed. Eating is a no-go.

not to mention the atmospheric compounds would almost definitely be different in some way, making it hard for humans to breath. I think enclosed outposts on foreign planets are mankind's best bet, at least until we have the technology to terraform on a large enough scale

neilzero
2012-Dec-16, 06:43 AM
8% oxygen and 91% nitrogen is likely ok for an hours breathing, at 3 atmospheres pressure but longer, some, perhaps most people will get nitrogen narcosis = rapture of the deep. Photo sythesis plants likely won't grow with less than 0.01% carbon dioxide at one atmosphere pressure. so it appears there are rather narrow restraints on a lot of things. Neil

ZunarJ5
2012-Dec-21, 09:50 PM
Teraforming is too big, domes are too limited, and space suits are too risky....

If we have the tech to reach and teraform distant worlds then certainly we have the tech to quickly modify ourselves. Why change the whole world when nano-tech and genetic engineering can more easily change us to adapt?

It would also be much more polite to the indigenous life forms.