We found one!

[steuard]

Wow oh wow. Universe Today just posted an article about an Earth-like planet discovered around a nearby red dwarf star. (The original source appears to be a UC Santa Cruz press release.)

It's right in the star's "habitable zone" (which mostly means "right temperature for liquid water") and has a mass about 3-4 times Earth's, so a quick estimate is that gravity there might be about 40% stronger than here (it wouldn't be too different than standing in an elevator as it gets going). That's plenty to hold an atmosphere. The planet has its quirks, of course: it's close to its cool sun, so a full orbit only takes about a month. Also, like our Moon it always has the same side facing "in": a planet of eternal sunlight on one side and eternal shadow on the other. Naturally, the only comfortable places to live would be in the twilight region encircling the planet between the extremes of hot and cold, where the red sun burns forever on the horizon.

This is awesome. And it's sooner than most people expected to find something like this, which may mean that planets like ours really are pretty common after all!

Now if only we could find a way to get there.

Comments

[kirin]

Maybe I should put my comment here rather than facebook for better discussion possibilities. Which was: This is indeed pretty awesome, but on two seconds of thought, a glut of habitable planets in the galaxy could imply not so great things about the probability of higher life evolving spontaneously, given we haven't seen any of it.

[steuard.livejournal.com]

Yeah, it would certainly remove one popular way of resolving the Fermi paradox.

Personally, I'm very happy to have a lot of other places out there where we could live, even if there's nobody living there now. But it's not clear how we'd see them unless they actually came here: think about how our use of radio, etc. is dropping now that we're shifting to the internet for communication! And it would take them a long time to personally visit any appreciable fraction of the stars in the galaxy!

[kirin]

True on general radio chatter - you'd have to happen to intersect a relatively thin expanding shell from the "radio-heavy period" of a civilization. On the other hand, a civilization past that point that was still interested in being found could purposely send signals in the direction of identified habitable planets. But of course, that's exactly the sort of thing SETI's looking for, and they've still only covered small fractions of the sky in any detail. And it could be that they *don't* particularly want to go out of their way to be found.

And yeah, uninhabited habitable planets are peachy if we ever develop practical interstellar travel. Unless it turns out the practical way to do it is to leave most of our biological shells behind, in which case habitability might not matter so much...

[steuard.livejournal.com]

a civilization past that point that was still interested in being found could purposely send signals in the direction of identified habitable planets.

Another suggestion that I saw a few years back was that more advanced civilizations may have found more effective means of communicating over vast distances. I read a paper discussing the advantages of neutrino communications over EM waves. It sounds like some of our newest neutrino detectors might be sensitive enough to pick up neutrino beam communications (the awesome Ice Cube that's based on a cubic kilometer of Antarctic ice, for example), and the technology for creating such a beam wouldn't be that far out of reach if we were really determined to make one.

Unless it turns out the practical way to do it is to leave most of our biological shells behind, in which case habitability might not matter so much

I don't know: I wouldn't be surprised if we came up of ways to avoid carrying biology along on the trip before we came up with ways of avoiding the need for it on the other end. (I'm envisioning something like an automated robotic nursery and learning center to raise children from frozen embryos, for example. Don't ask me too much about the ethics of that, but I might still prefer that scenario to never "getting out" at all.)

[spoonless.livejournal.com]

Unfortunately, I think the more likely conclusion is that intelligent life just always blows itself up with nukes or bioweapons after reaching a certain stage of development, shortly after us.

[steuard.livejournal.com]

Oh, so pessimistic! At least give us the option of death by VR!

But also, I'm skeptical of this sort of argument in part because it seems to generalize so broadly from human psychology. It doesn't feel like we're that far from the "not blowing ourselves up" edge, culturally speaking, though I'll admit it's a risk. So given that aliens could be enormously different from us or anything we've imagined, it's hard for me to believe that they'd all self-destruct.

That's why the "slow exploration, lots of stars" argument starts to feel tempting to me. Maybe an advanced civilization is always forced to adopt a culture of linear population growth (rather than exponential) to survive until interstellar travel becomes available, and that limits the rate at which they spread.

[spoonless.livejournal.com]

A quick check reveals that the official "Doomsday Clock" is at 11:54, 6 minutes to midnight...

http://en.wikipedia.org/wiki/Doomsday_Clock

Of course, I don't take that particular clock all that seriously. They might as well have chosen a calibration where we are an hour from midnight, or a day from midnight, or anything. But the idea of countries like Pakistan having nukes, and soon countries like Iran and North Korea, does kinda scare the crap out of me. And that's just nukes, which are fairly hard to transport around. What happens when it gets a lot easier to engineer viruses like Ebola, and terrorists can carry them around in their underwear? As much as I love technology, I think the problem is that the more advanced the technology gets, the more it only takes a few bad apples to do a lot of damage.

I do think the VR thing is a possibility.

The main resolution I like for the fermi paradox is just that there aren't enough civilizations close enough to us... the ones far away are just too far away, and aren't directing anything at us. That one seems the most reasonable to me. But this gets less likely as we discover more earthlike planets.

I agree, it's hard to say how much we can generalize from human psychology. But if there's one thing I would count on being a pretty general consequence of any form of evolved life, it is some kind of competitive instinct, coming from the basic mechanism that drives evolution which is competition over natural resources.