I’ll have a piece up at PJMedia tomorrow on Kepler and the discovery of an earth-sized planet in a habitable zone, but meanwhile, Jeff Foust reviews a new book by a researcher who says that planets that can accommodate LAWKI aren’t as common as some are saying.
14 thoughts on “Earth-Like Planets”
I personally think his thesis is overly pessimistic about the quantity of habitable planets out there, but I have also thought that the other side of the argument is too optimistic, so reality is probably somewhere in the middle.
Heck, I would not be surprised at all if the majority of the planets that are right in the middle of their star’s Goldilocks zone, and have the markers for possibly having life, had a large moon and had a lot of parallels to the Earth-Moon system. That stability seems to be a very important reason for why things happened here, the way they did, including the occasional reset button we call asteroid strikes…
But as we have seen time and time again, the universe is a strange, wonderful place, and we really only know a thimbleful at this point, so who knows. And who said that carbon based, oxygen eaters like us have to be the only way for life to evolve…
Having the gas giants located in the outer solar system is a big help also .. they sweep up a lot of rocks from the ort cloud and kiper belt.
It is well to note that if Aliens had shown up on Earth during its first 4 billions years all they would have found would have been bacteria. And if they had shown up in the first 4.3 billion years they would have found no life on land beyond bacteria. The question is why are those larger steps then the step to creating bacteria.
That said, there could be lots of planets out there, like the Earth was during its first 4.3 billion years, well suited to terra forming for humans.
The 4 billion year stumbling block was in convincing some bacteria that they shouldn’t all be equal, have the same status, and get the same rewards. Every time they came together to form a halfway successful organism, malcontents would go on strike or too much metabolism would be devoted to subject the individual cells to gender equity training.
Anyway, the book sounds very much like “Rare Earth” (Amazon link) which I greatly enjoyed.
The alternative idea is that every planet in the galaxy looks suspiciously like places around Vancouver.
True. for 4 Billion years, the Earth was slime world, until the last Snowball Earth melted. Not an appealing place to look for higher life forms, but yeah, given how fast everything took off in the Cambrian Explosion, it would have been a simple matter to terraform a planet in that stage. Heck, even with the Snowballs, has anyone really been able to figure out why life went nuts in such a short (geologically speaking) time after 4 Billion years of blue green algae???
The best theory I’ve heard is that cells finally developed genes like Hedgehog (and Sonic Hedgehog), which allows cells to differentiate into complex structures. Once there was a mechanism in place for building complex multicellular structures according to a body plan, evolution had something to act on.
Mercury, mars and venus are earth like planets not 490 ly away. Exoplanets are exciting, but what’s wrong with the girl we brung to the dance?
Not a thing, but unless something drastic happens, or the aliens really are standing behind Opportunity and Curiosity laughing their butts off where we can’t see them, the odds are not good we will find higher life here in our local neighborhood…
Yeah, I can’t find any.
I think LAWKI would see us as food, so why bother colonizing such a world?
And I’m not just thinking of megafauna. Anybody read Andromeda Strain?
Who reads? We all saw the movie.
We aren’t just lucky. We are lucky beyond all reason. We should use that luck to settle the unlucky ones.
Oort cloud, here we come.
From what I understand, these are worlds whose existence is inferred from spectroscopic or light curve measurements. Based upon those noisy numbers, the conclusion is that a world of a given mass orbits at a given distance from the primary. And based upon the primary’s spectral type, if a world is in a particular range of distances, then it is considered “habitable.” We’ve yet to detect anything like oxygen or water vapor on any of these worlds, since we can’t even come close to imaging them.
In other words, we have no idea of what these worlds are like, other than some of them seem to fit the model of this solar system, and others ware wildly different. But it does make good sensationalistic copy.
I personally think his thesis is overly pessimistic about the quantity of habitable planets out there, but I have also thought that the other side of the argument is too optimistic, so reality is probably somewhere in the middle.
Heck, I would not be surprised at all if the majority of the planets that are right in the middle of their star’s Goldilocks zone, and have the markers for possibly having life, had a large moon and had a lot of parallels to the Earth-Moon system. That stability seems to be a very important reason for why things happened here, the way they did, including the occasional reset button we call asteroid strikes…
But as we have seen time and time again, the universe is a strange, wonderful place, and we really only know a thimbleful at this point, so who knows. And who said that carbon based, oxygen eaters like us have to be the only way for life to evolve…
Having the gas giants located in the outer solar system is a big help also .. they sweep up a lot of rocks from the ort cloud and kiper belt.
It is well to note that if Aliens had shown up on Earth during its first 4 billions years all they would have found would have been bacteria. And if they had shown up in the first 4.3 billion years they would have found no life on land beyond bacteria. The question is why are those larger steps then the step to creating bacteria.
That said, there could be lots of planets out there, like the Earth was during its first 4.3 billion years, well suited to terra forming for humans.
The 4 billion year stumbling block was in convincing some bacteria that they shouldn’t all be equal, have the same status, and get the same rewards. Every time they came together to form a halfway successful organism, malcontents would go on strike or too much metabolism would be devoted to subject the individual cells to gender equity training.
Anyway, the book sounds very much like “Rare Earth” (Amazon link) which I greatly enjoyed.
The alternative idea is that every planet in the galaxy looks suspiciously like places around Vancouver.
True. for 4 Billion years, the Earth was slime world, until the last Snowball Earth melted. Not an appealing place to look for higher life forms, but yeah, given how fast everything took off in the Cambrian Explosion, it would have been a simple matter to terraform a planet in that stage. Heck, even with the Snowballs, has anyone really been able to figure out why life went nuts in such a short (geologically speaking) time after 4 Billion years of blue green algae???
The best theory I’ve heard is that cells finally developed genes like Hedgehog (and Sonic Hedgehog), which allows cells to differentiate into complex structures. Once there was a mechanism in place for building complex multicellular structures according to a body plan, evolution had something to act on.
Mercury, mars and venus are earth like planets not 490 ly away. Exoplanets are exciting, but what’s wrong with the girl we brung to the dance?
Not a thing, but unless something drastic happens, or the aliens really are standing behind Opportunity and Curiosity laughing their butts off where we can’t see them, the odds are not good we will find higher life here in our local neighborhood…
Yeah, I can’t find any.
I think LAWKI would see us as food, so why bother colonizing such a world?
And I’m not just thinking of megafauna. Anybody read Andromeda Strain?
Who reads? We all saw the movie.
We aren’t just lucky. We are lucky beyond all reason. We should use that luck to settle the unlucky ones.
Oort cloud, here we come.
From what I understand, these are worlds whose existence is inferred from spectroscopic or light curve measurements. Based upon those noisy numbers, the conclusion is that a world of a given mass orbits at a given distance from the primary. And based upon the primary’s spectral type, if a world is in a particular range of distances, then it is considered “habitable.” We’ve yet to detect anything like oxygen or water vapor on any of these worlds, since we can’t even come close to imaging them.
In other words, we have no idea of what these worlds are like, other than some of them seem to fit the model of this solar system, and others ware wildly different. But it does make good sensationalistic copy.
http://www.science20.com/quantum_gravity/blog/a_better_than_5050_chance_kepler186f_has_technological_life-134555