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NASA Confirms Its First Planet in Habitable Zone of Sun-like Star

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Re: NASA Confirms Its First Planet in Habitable Zone of Sun-like Star

#31

Post by polyfractal »

maratd wrote: post #21
cryptoz wrote: post #12

Earlier quoted context omitted.

> Taking this a step further, finding intelligent life out there is simply impossible What? How can you take this position? That's absolutely crazy. Really, you're going to take observations from just a couple of decades and determine that finding something is "impossible"?! No way. There's absolutely no way that finding intelligent life is impossible. > The reason our intelligence is unique to only humans on our pla…

> Slow down there. Nobody is looking for "human intelligence" on other planets. Maybe that's why you think it's impossible. I'd say dolphins are intelligent. So are some of our computer systems. There's a lot more intelligence that we can recognize that isn't like ours. When I think of intelligent alien life, I think along the lines of Klingons, not alien dolphins. Are we going to find alien dolphins? Absolutely. Kli…

So if some alien spaceship flew up to the planet Earth today, you'd say they aren't intelligent? Just alien dolphins that happen to have built spaceships? What?

I don't even know what you are arguing against.

Re: NASA Confirms Its First Planet in Habitable Zone of Sun-like Star

#32

Post by yread »

Florin_Andrei wrote: post #27
yread wrote: post #24

I highly recommend reading the wikipedia article (which, of course, has already been partly updated from this press release). http://en.wikipedia.org/wiki/Kepler_(spacecraft) you will find out that: - it has 42 sensors with 95 MPixel resolution total - they only cover 10 square degrees of sky - only 150k stars were selected for monitoring the rest of the pixels is thrown out - they are read out every six seconds and…

they only cover 10 square degrees of sky "only", heh (BTW, it's 12 linear degrees, 105 square degrees) It's hard to make instruments that provide good images across wide angles. Many visual telescopes, both amateur and professional, stay at 1 degree and less of true field of view for medium and high magnification; 2 degrees true field is already pretty good and it's usually obtained at low magnification. Astrographs…

oh, you're right I got confused by the mention of HST.

> 0.1 arcsec, or 6 arcmin

I'm pretty sure 0.1 arcsec isn't 6 arcmin :) it's less than 0.002 arcmin

Re: NASA Confirms Its First Planet in Habitable Zone of Sun-like Star

#33

Post by mirkules »

jjcm wrote: post #19

What's the gravity on the surface? It's 2.4 times the size of earth, is the density the same? If so, that amount of gravity may very well make it uninhabitable.

Humans can withstand much more than 2.4Gs although the time is exponentially and inversely proportional (for example, 3Gs is a space shuttle launch for a number of minutes, 10Gs is the maximum force allowed during space capsule landing, but only for a few seconds).

Therefore, I wouldn't say "uninhabitable," but probably less friendly (and not immediately lethal) to humans. Also, different animals have different thresholds -- mice, for example, have a much lower tolerance for G-forces than whales.

I recommend reading "Packing for Mars" by Mary Roach -- very insightful book that discusses all sorts of things about planet habitability, space travel, space suit design, psychology, and among many other things, G-forces.

Re: NASA Confirms Its First Planet in Habitable Zone of Sun-like Star

#34

Post by CWuestefeld »

davedx wrote: post #16
cletus wrote: post #2

Kepler has certainly made a lot of discoveries. It should be fairly clear to us now that planetary systems are pretty common and, by extension, sentience must (by sheer odds) be out there too. But I have to wonder how many assumptions go into this so-called "habitable zone". Doesn't it greatly depend on the atmospheric composition? With a different atmosphere, couldn't Venus be habitable (actually it might be in our…

The 'habitable zone' is overly simplistic in general. Look at Europa - it's nowhere near the habitable zone, but is one of the most Earth-like plants in our Solar System. That's just inside the one Solar System we have a fairly complete planetary record of! It also assumes that liquid water and an oxygen atmosphere are prerequisites for life. Extremophiles [1] living on our own planet prove that this is not so. [1] h…

It also assumes that liquid water and an oxygen atmosphere are prerequisites for life. Extremophiles living on our own planet prove that this is not so.

Maybe this is splitting hairs, but we have evidence that life can exist in such extreme condition. We have no evidence that life can arise under those conditions. I think it's perfectly plausible that it's path-dependent: life needs the friendlier conditions to first develop; once it's up and running with a means of evolving, it's able to acclimatize gradually to the extremes.

If I'm right, then it's still correct to exclude worlds that could never have had the "correct" conditions.

Re: NASA Confirms Its First Planet in Habitable Zone of Sun-like Star

#35

Post by Florin_Andrei »

yread wrote: post #32
Florin_Andrei wrote: post #27

Earlier quoted context omitted.

they only cover 10 square degrees of sky "only", heh (BTW, it's 12 linear degrees, 105 square degrees) It's hard to make instruments that provide good images across wide angles. Many visual telescopes, both amateur and professional, stay at 1 degree and less of true field of view for medium and high magnification; 2 degrees true field is already pretty good and it's usually obtained at low magnification. Astrographs…

oh, you're right I got confused by the mention of HST. > 0.1 arcsec, or 6 arcmin I'm pretty sure 0.1 arcsec isn't 6 arcmin :) it's less than 0.002 arcmin

Huh. Not enough caffeine (grumble).

It's actually funny the way I made the mistake; things got flipped at a semantic level, above syntax. I guess a neuroscientist would see some significance in it, or something.

Re: NASA Confirms Its First Planet in Habitable Zone of Sun-like Star

#36

Post by kiba »

mapster wrote: post #18
maeon3 wrote: post #11

We are rapidly approaching the day where humans can colonize other worlds. maybe that is how we got here.

We are in a new space race, since we are also rapidly approaching the day that our Earth will be inhabitable.

Excuse me, uninhabitable?

I don't think our planet is going to become uninhabitable, not by a long shot.

Re: NASA Confirms Its First Planet in Habitable Zone of Sun-like Star

#37

Post by InclinedPlane »

marshallp wrote: post #15
blhack wrote: post #6

Earlier quoted context omitted.

>sentience must (by sheer odds) be out there too. Why? Sentience just happens to be an evolutionary trait that was beneficial to us, like wings on a bird. There millions of species animals on our planet, and only a handful of them are sentient. We have a bit of a cognitive bias towards thinking that sentient life is something that evolution would work towards, but that isn't really how evolution works.

There's a fundamental flaw in that argument. Once a sentience, or as i would define it, a species capable of creating technology, exists, it is highly likely to not die out as other traits easily can. It only needs to occur once. One could argue it has -almost- occurred on earth many times, including dolphins, elephants, octopus along with apes right now.

A lot of the more grandiose doom-and-gloom scenarios put forth regarding global warming are a bit overwrought. The Earth will continue to harbor life even if we pumped all of the carbon from every fossil fuel on the planet into the atmosphere. The main issue is that such a world will be different, it may have different species (more of some, less or none of some we've come to know) and it may be more difficult for human civilization to exist. But there's absolutely no risk of human activity re: CO2 emissions in making the Earth uninhabitable.

Re: NASA Confirms Its First Planet in Habitable Zone of Sun-like Star

#38

Post by Tossrock »

nickpinkston wrote: post #23
cryptoz wrote: post #20

Earlier quoted context omitted.

They don't know the density yet, but future observations should tell us. Probably next year, I think.

Wait - we can't infer this using orbit size and speed plus the volume of body? Is it more about distribution of density throughout the body?

Orbit size and speed have no relation to planetary density by themselves. If we knew the total kinetic energy of the planet, then they would, but we don't.

Re: NASA Confirms Its First Planet in Habitable Zone of Sun-like Star

#39

Post by chc »

maeon3 wrote: post #11

We are rapidly approaching the day where humans can colonize other worlds. maybe that is how we got here.

Not that close, since with the fastest vehicles we've ever built, it would take something like a million years to reach even the closest star. If we can figure out how to survive in the harsh environment of space for millennia, it seems like we're pretty much past the need for colonization.

Re: NASA Confirms Its First Planet in Habitable Zone of Sun-like Star

#40

Post by mapster »

kiba wrote: post #36
mapster wrote: post #18

Earlier quoted context omitted.

We are in a new space race, since we are also rapidly approaching the day that our Earth will be inhabitable.

Excuse me, uninhabitable? I don't think our planet is going to become uninhabitable, not by a long shot.

excuse me, yes, I intended to write UN-inhabitable. Its a fear I think is well founded considering global poisoning of air and water, CO2 emissions, uncontrolled population growth and threats to global food production capabilities, and alarming rate of rogue nations with nuclear missiles. Give that another 200 years to take us to the brink. Humans are great at exploration (continents or space), but lousy at stopping or changing their own behavior.
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