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(Telegraph)   Astronomers find first planet in the sweet spot of the habitable zone, capable of supporting intelligent life   (telegraph.co.uk) divider line 123
    More: Misc, planets, habitable zones, red dwarf stars, radial velocity, astronomers, extrasolar planets, planetary habitability, light-years  
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6968 clicks; posted to Geek » on 27 Apr 2012 at 12:58 PM (2 years ago)   |  Favorite    |   share:  Share on Twitter share via Email Share on Facebook   more»



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2012-04-27 11:55:12 PM

GAT_00: gameshowhost: Jubeebee: gameshowhost: GAT_00: Around a red dwarf? Yeah, it's tidally locked.

I'm no astrophysicist, so I need to ask... from what does 'in orbit around a red dwarf' necessarily imply 'tidally locked'?

I'm guessing here, but maybe because the habitable zone around a red dwarf is so close to the star that any rocky planet would necessarily be so deep in the gravity well that it would have to be tidally locked.

Ya, some Googling confirms that such w/ liquid water are highly likely to be tidally locked... not 'necessarily implies' but close enough. IT'S LEGIT TO ME

Yeah, that's it. That takes time too, so if it's a young red dwarf, it still may be rotating. But basically when a planet is close to the sun it tends to rotate slower. There's a fair bit of math behind that, but for example, you know Venus and Mercury rotate exceptionally slowly, so their days are nearly as long, or longer in Mercury's case, than their year. That's an effect due to proximity to the sun. Red dwarfs are much cooler, so a habitable zone is very close to the sun. However, red dwarfs don't mass much less, so it's likely to be tidally locked.


Venus isn't really a good example; it's the only planet with a retrograde rotation, which suggests that it was hit by an object so massive that it's rotation was reversed. Its current motion may not be a function merely of gravitational forces.
 
2012-04-28 02:37:59 AM
Cracked had something on this not long ago...

Here it is
i.crackedcdn.com
So to summarize: red skies, black plants, gale winds, never-ending twilight and a step too far in one direction could lead to either freezing to death or incineration.
So it's probably best to check with MapQuest before even going down the block.
And yet, rather than tiptoeing around that planet and looking for life somewhere a little less terrifying, we're doing our best to wake up whatever nightmare might be living there already. In October 2008, we sent a message from Earth directly at Gliese 581 c, and it should reach the devil planet around 2029.


/that's 581C though, I'm sure this one is much safer...
 
2012-04-28 03:13:47 AM
Venus, Mars, the Moon, and Ceres are also in the habitable zone.


But this is awesome.
 
2012-04-28 04:30:35 AM

MindStalker: FTA: as 20 years ago scientists were still arguing about the existence of planets beyond our solar system.

Really? I'm having a hard time believing that any credible scientist 20 years ago thought that other suns wouldn't have bodies of rock or gas orbiting them.


20 years ago, there was no evidence to support the idea. Science isn't about what scientists think (except for climate science).
 
2012-04-28 04:43:22 AM

Brainsick: /that's 581C though, I'm sure this one is much safer...


Gliese 436b is where you want to be. It has ice-ten, one worse than ice-nine.
 
2012-04-28 08:10:53 AM

deffuse: Shouldn't that be the second?


"intelligent"
 
2012-04-28 09:40:03 AM
 
2012-04-28 10:54:51 AM
Did they also discover time travel? Because I know I've seen this at least six times now. Gliese, too, no less.
 
2012-04-28 11:46:51 AM
Astronomers find new planet capable of supporting hype

It's evolving!
 
2012-04-28 01:25:36 PM
malaktaus

Venus isn't really a good example; it's the only planet with a retrograde rotation, which suggests that it was hit by an object so massive that it's rotation was reversed. Its current motion may not be a function merely of gravitational forces.

Well, that explains women.
 
2012-04-28 02:01:14 PM

malaktaus: mr lawson: busy chillin': many of you are way way smarter than me, but if a bunch of these meteorites are flying around there is a chance that there is life somewhere in the universe, or the chance that life could start somewhere if one these land on the right planet.

Am I right in thinking this?

/love thinking about this stuff

better yet....the asteroid that hit the earth that kill off the T-rex put a lot of earth material (which had life in it) into space. That stuff could be landing on habitable planets right now seeding life.

There is absolutely zero chance it has reached any habitable planet, nor will it for many millions of years.


*basic math time*
Earth's escape velocity= ~25,000 mph
24 hr day* 25,000= 600,000 miles a day

time ago that asteroid that killed off "Barney"= 65 million years or 23,725,000,000 days
600,000* 23,725,000,000=***************14,235,000,000,000,000 miles
one light year=**************************************5,878,499,810,000 miles
really Big number/big number=~2454.31 light years stuff could have traveled
 
2012-04-28 02:03:40 PM

busy chillin': malaktaus

Venus isn't really a good example; it's the only planet with a retrograde rotation, which suggests that it was hit by an object so massive that it's rotation was reversed. Its current motion may not be a function merely of gravitational forces.

Well, that explains women.


Venus isn't really a good example; it's the only
planet
with a retrograde rotation,
`
Ahm, Uranus would like a word with you
 
2012-04-28 04:08:00 PM

Bevets: Astronomers find new planet capable of supporting hype


FTA: "Currently, they can detect planets which are 3-5 times the mass of the Earth but, in the future, they could detect planets which are smaller than twice the mass of Earth."

So yes, it's a holy grail because it shows that other planets do exist within the habitable zone around other stars even though that was an assumption it's now been shown via evidence. Of course the anti science creationist website you quoted failed to mention any part of that.
 
2012-04-28 04:51:03 PM

Cagey B: Capable of supporting Earth-like life, perhaps. I'm tired of the assumption that any form of life that occurs in the universe will look anything like what it does here.


Dear gods, this.

One of the things I did like about the Chanur Saga series of sci-fi novels is--despite the Space Furries along with the Not-Really-Greys--they DID have some species, largely methane-breathers, that were TRULY alien...and probably closer to what we'd encounter upon such time that we ever ran into sophont life.

(For example--the least alien methane-breathers in that sci-fi-verse are the T'ca, which are basically a race of giant sandworm-looking things that functionally have five brains and speak in five-part harmonic matrices with multiple levels of meaning depending on if the translated text is read across, down, or diagonally--and all are equally valid. They pretty much act as translators for the OTHER methane-breather races which are pretty much completely and utterly incomprehensible to the others in this trade alliance in the books.)

The Space Hospital series is also fairly decent in trying to portray non-humanoid alien sophonts (very often non-bilaterian alien sophonts) in a non-nightmare-fuel context (there's always Lovecraft, but I think we can all agree that's nightmare fuel :D).

/if we ever find non-carbon-based sophont life, I seriously doubt we'll ever recognise it as life, much less as intelligent life
//hell, we have issues talking with the quite-possibly-intelligent-life on our OWN planet in the form of delphiniform cetaceans--you know--Flipper and Shamu and the like
 
2012-04-28 05:04:53 PM

I alone am best: Mad_Radhu: Cagey B: Capable of supporting Earth-like life, perhaps. I'm tired of the assumption that any form of life that occurs in the universe will look anything like what it does here.

It's easy to day there could be alternative biochemistry involved, but when you start looking into the details of how those biochemistries would function you start running into problems where the chemical bonds formed by silicon are too strong for it to make a good alternative to carbon, and ammonia makes a crappy substitute for water due to weak hydrogen bonds and a low surface tension. Plus you have the fact that hydrogen, oxygen, and carbon are among the most common elements in the universe, so it isn't an accident that they are used for biological processes.

We'll see what happens when we look more closely at moons like Titan in the outer solar system where methane-based life might work, but it's possible that the basic chemistry just doesn't work out on forms of life that are too far removed from our own. I'd love to see some really exotic life, but reading about some of the problems with alternative biochemistry gives me some cause to think it just isn't as easy getting life started with those building blocks.

Additionaly given the same conditions on the planet(I.E. gravity, atmospheric pressure, carbon based life blah blah blah). I wouldn't think life from another planet would be all that much different in appearance than life on earth.


I'd be careful in assuming even life on an earth-like planet with similar biological processes would be similar to us, at least on the macro-level.

For example, there's a shiatload of fossils from the Ediacaran era (pretty much the dawn of multicellular life and where it's thought the ancestors of modern kingdoms of life originated from) that are so friggin' alien to us--we can't even really classify them other than saying "OK, this is definitely multicellular life. We can't even tell if this is unikont or bikont multicellular life, much less classify it as an animal or plant or type of fungi, though". Many, if not most, Ediacaran life forms may as well be from another planet...as much as we can tell about them, anyways.

It's entirely possible if the Ediacaran-Cambrian extinction event had gone a bit differently...much less if the Cambrian-Ordovician extinction had gone differently...if sophont life had evolved (never a guarantee) it might not even be bilaterial or animal life, much less anything humanoid. Hell, if early chordates might not have made it, the dominant form of life with a POSSIBILITY of evolving into intelligence would be closer to octopi than anything else. :P
 
2012-04-28 07:38:44 PM

mr lawson: really Big number/big number=~2454.31 light years stuff could have traveled


Basically this. Except that we don't know for sure if life didn't arrive here on one of these rocks. If it did then the abiogenesis could have happened anywhere in the galaxy, billions of years ago. The whole thing could be contaminated by now.
 
2012-04-28 07:39:41 PM
I had to look up "sophont"...

/Thanks for the lexicon addition. Not that I'm likely to ever use it, but it could come in handy for a crossword puzzle someday.
 
2012-04-28 10:53:11 PM
Having just arranged to start doing some work on Planetary detection using gravitational micro-lensing (many yays were had), I should probably be getting a kick out of this.
 
2012-04-29 12:21:10 AM

babtras: traylor: With 4.5 times earth mass, I think it's probably inhabited by creatures with more than two legs. See, eight legs would be ideal to withstand the gravity of this planet..

If the planet is the same composition as Earth, then the surface gravity will only be 1.65G. 2 or 4 legs is still sufficient. I believe higher gravity will mean smaller creatures rather than beefier ones. Many of the planets being discovered have significantly lower densities than Earth. If this planet were closer in density to the water rich planets and moons in our solar system, the surface gravity could be as low as 0.8G, and would potentially have a very thick atmosphere, leading to increased buoyancy and might be able to fly by flapping our arms.


I think your math is off, but I could be wrong too. Let me bounce this off you:

F = G*m1*m2/r^2, where F on earth is 9.8N, which is 1g.

Assuming both planets have the same density, the exoplanet has a mass of 5*m1.

But the volume (assuming both planets are spherical, is 4/3πr^3) increases by a factor of 5 if the densities are the same, which means the radius increases by the cubic root of 5. So instead of 1 Earth radius, it is 2.2457 Earth radii, which, when squared, equals 5.

Plug that into the original equation, and gravity doesn't change.

Right?
 
2012-04-29 02:52:51 AM
By any chance is it named Polyphemus with a moon orbiting it named Pandora?
 
2012-04-29 09:58:52 AM

mainstreet62: means the radius increases by the cubic root of 5. So instead of 1 Earth radius, it is 2.2457 Earth radii, which, when squared, equals 5


Bzzt. The square of the cube root of 5 is not 5.

So, the gravity should be 5 over (cube root of 5 squared) times earth, or cube-root-5 time earth, or about 1.71 earth-g.

It's also assuming nickel-iron planet stuff is incompressible. It's not particularly compressible, admittedly, but with the weight of a planetary mass, it might do so enough to have a noticeable impact on the gravity -- maybe a couple percent?.
 
2012-04-29 11:07:04 AM

mr lawson: malaktaus: mr lawson: busy chillin': many of you are way way smarter than me, but if a bunch of these meteorites are flying around there is a chance that there is life somewhere in the universe, or the chance that life could start somewhere if one these land on the right planet.

Am I right in thinking this?

/love thinking about this stuff

better yet....the asteroid that hit the earth that kill off the T-rex put a lot of earth material (which had life in it) into space. That stuff could be landing on habitable planets right now seeding life.

There is absolutely zero chance it has reached any habitable planet, nor will it for many millions of years.

*basic math time*
Earth's escape velocity= ~25,000 mph
24 hr day* 25,000= 600,000 miles a day

time ago that asteroid that killed off "Barney"= 65 million years or 23,725,000,000 days
600,000* 23,725,000,000=***************14,235,000,000,000,000 miles
one light year=**************************************5,878,499,810,000 miles
really Big number/big number=~2454.31 light years stuff could have traveled


Great, except escape velocity is the speed it's going right after impact. What you're interested in is how much *faster* than that it was going initially. That will tell you the surplus kinetic energy it still has after escaping Earth's gravity well. So your calculation is great, if the ejected material happened to be going twice escape velocity. but I don't see any reason to believe that it wasn't instead going 1 mm/year over escape velocity.
 
2012-04-29 12:42:14 PM

Boatmech: busy chillin': malaktaus

Venus isn't really a good example; it's the only planet with a retrograde rotation, which suggests that it was hit by an object so massive that it's rotation was reversed. Its current motion may not be a function merely of gravitational forces.

Well, that explains women.

Venus isn't really a good example; it's the only
planet with a retrograde rotation,
`
Ahm, Uranus would like a word with you



Pshaw. If I wanted to hear from Uranus, I'd [***CARRIER LOST***]
 
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