4 ms·

I wonder what Kepler 186f thinks of Earth?

XorNot 12y ago
"Smaller, hotter, but in the habitable zone of it's star. Relpek 681f orbits a hot yellow star but far enough out to not be cooked by it. Yellow stars are so hot that they would turn our planet into a barren, semi-molten wasteland at the same distance. Scientists have noted that the atmosphere of Relpek 681f would have to be very thin in order for it to maintain cool enough temperatures, but it's well known that plant life would probably have an easier time dealing with it's solar radiation output..."
- FlailFast 12y ago
  Now I want a subscription to the Keplerian Journal of Science.
- rbanffy 12y ago
  "It's also a very young system and there hasn't been enough time for it to develop any form pf intelligent life."
- ksrm 12y ago
  Side note: we would be Relpek 681d (b=Mercury, c=Venus).
Udo 12y ago
Thinking about what Earth and its star system look like from the outside is indeed a very interesting exercise, and it gives you an idea how flawed many of our own assumptions about exobiology may be. At these distances, our radio spectrum would be difficult to discern from random galactical noise - even if the radio waves had enough time to cross the distance. And in fact, so far it looks like the more advanced we get the less telling our radio signature becomes. There are no large-scale constructs or artifacts visible that hint at any technological activity in the solar system. Looking at how crowded the solar system is, an onlooker might well assume it's too unstable for life to have developed. The Earth might be seen as too small to support life, its atmosphere too thin to shield against radiation and also too thin to allow for a comfortable temperature interval in which liquid water exists. Due to the difficulties of aerodynamic flight under these circumstances, they can safely assume there will be no winged lifeforms on Earth. They might also think that any plant life on Earth would be extremely sparse and desolate - yet the abundance of oxygen hints at a world dominated by microbial life. The orbital and rotational instability of the planet leads to wild temperature variations which will likely prevent the rise of higher life forms. The presence of several semi-unstable interplanetary debris fields suggests asteroid impacts will be frequent, and likely to extinguish life on any of the planets. The relative proximity and high mass of the Earth's moon (or shall we say: sister planet) makes it likely that the planet will be subject to tidal disturbances and might imply a history of extreme geological instability. Water covers a large part of the Earth's surface, but generally is only present in the form of very shallow oceans tainted with poisonous chloride salts in high concentrations. It's unclear if unchlorinated water exists on the surface and in any case it's doubtful that there's enough water to form a stable cycle able to support any but the most primitive extremophiles.
- jerf 12y ago
  The "planet much harsher than Earth that develops an extremely aggressive, warlike lifeform far stronger than us" is an old science fiction trope. One of the most popular examples are the Klingons. But what if Earth is that planet? Obviously it can support intelligent life, but while there's lots of ways it could be harsher, there's also lots of ways it could be friendlier. For instance, it would be nice if this ice age that we're in the middle of wasn't happening. (Incidentally, you can add that to your list of reasons why Earth can't possibly support advanced life... it's spent an awful lot of time nearly entirely frosted over lately. http://xkcd.com/1225/ http://xkcd.com/1225/ )
  - Udo 12y ago
    > Incidentally, you can add that to your list of reasons why Earth can't possibly support advanced life I did think of that, read the comment again - it's the one about the extreme temperature variations which prevent higher life forms from arising :) But yeah, harsher environments leading to harsher species feels instinctively right, though on the other hand what's considered a strength on one world will be a weakness on many others. On Earth, most life is coupled pretty tightly to the local conditions and that's why so many species die off whenever some minute changes occur. Luckily, there are more resilient generalists around as well, like us. And if technology-producing intelligence is a generalist trait, we could assume life on other worlds to be similar in that regard. Intellectual generalism seems to require, or at least strongly favor, a departure from innate mental dispositions in favor a cultural imprinting. So that leaves some measure of hope that, whatever an intelligent species' origins, traits such as being warlike might not be inescapable. Anyway, it's unlikely there are Klingon-style people out there who can just come here and perform much better in our own environment than us, the natives. At least not without massive technological help, which kind of nullifies the importance of biological strength.
    - jerf 12y ago
      "I did think of that, read the comment again - it's the one about the extreme temperature variations which prevent higher life forms from arising :)" Ah, sorry.

"Smaller, hotter, but in the habitable zone of it's star. Relpek 681f orbits a hot yellow star but far enough out to not be cooked by it. Yellow stars are so hot that they would turn our planet into a barren, semi-molten wasteland at the same distance. Scientists have noted that the atmosphere of Relpek 681f would have to be very thin in order for it to maintain cool enough temperatures, but it's well known that plant life would probably have an easier time dealing with it's solar radiation output..."

FlailFast 12y ago
Now I want a subscription to the Keplerian Journal of Science.
rbanffy 12y ago
"It's also a very young system and there hasn't been enough time for it to develop any form pf intelligent life."
ksrm 12y ago
Side note: we would be Relpek 681d (b=Mercury, c=Venus).

Udo 12y ago

Thinking about what Earth and its star system look like from the outside is indeed a very interesting exercise, and it gives you an idea how flawed many of our own assumptions about exobiology may be. At these distances, our radio spectrum would be difficult to discern from random galactical noise - even if the radio waves had enough time to cross the distance. And in fact, so far it looks like the more advanced we get the less telling our radio signature becomes. There are no large-scale constructs or artifacts visible that hint at any technological activity in the solar system. Looking at how crowded the solar system is, an onlooker might well assume it's too unstable for life to have developed. The Earth might be seen as too small to support life, its atmosphere too thin to shield against radiation and also too thin to allow for a comfortable temperature interval in which liquid water exists. Due to the difficulties of aerodynamic flight under these circumstances, they can safely assume there will be no winged lifeforms on Earth. They might also think that any plant life on Earth would be extremely sparse and desolate - yet the abundance of oxygen hints at a world dominated by microbial life. The orbital and rotational instability of the planet leads to wild temperature variations which will likely prevent the rise of higher life forms. The presence of several semi-unstable interplanetary debris fields suggests asteroid impacts will be frequent, and likely to extinguish life on any of the planets. The relative proximity and high mass of the Earth's moon (or shall we say: sister planet) makes it likely that the planet will be subject to tidal disturbances and might imply a history of extreme geological instability. Water covers a large part of the Earth's surface, but generally is only present in the form of very shallow oceans tainted with poisonous chloride salts in high concentrations. It's unclear if unchlorinated water exists on the surface and in any case it's doubtful that there's enough water to form a stable cycle able to support any but the most primitive extremophiles.

jerf 12y ago
The "planet much harsher than Earth that develops an extremely aggressive, warlike lifeform far stronger than us" is an old science fiction trope. One of the most popular examples are the Klingons. But what if Earth is that planet? Obviously it can support intelligent life, but while there's lots of ways it could be harsher, there's also lots of ways it could be friendlier. For instance, it would be nice if this ice age that we're in the middle of wasn't happening. (Incidentally, you can add that to your list of reasons why Earth can't possibly support advanced life... it's spent an awful lot of time nearly entirely frosted over lately. http://xkcd.com/1225/ http://xkcd.com/1225/ )
- Udo 12y ago
  > Incidentally, you can add that to your list of reasons why Earth can't possibly support advanced life I did think of that, read the comment again - it's the one about the extreme temperature variations which prevent higher life forms from arising :) But yeah, harsher environments leading to harsher species feels instinctively right, though on the other hand what's considered a strength on one world will be a weakness on many others. On Earth, most life is coupled pretty tightly to the local conditions and that's why so many species die off whenever some minute changes occur. Luckily, there are more resilient generalists around as well, like us. And if technology-producing intelligence is a generalist trait, we could assume life on other worlds to be similar in that regard. Intellectual generalism seems to require, or at least strongly favor, a departure from innate mental dispositions in favor a cultural imprinting. So that leaves some measure of hope that, whatever an intelligent species' origins, traits such as being warlike might not be inescapable. Anyway, it's unlikely there are Klingon-style people out there who can just come here and perform much better in our own environment than us, the natives. At least not without massive technological help, which kind of nullifies the importance of biological strength.
  - jerf 12y ago
    "I did think of that, read the comment again - it's the one about the extreme temperature variations which prevent higher life forms from arising :)" Ah, sorry.