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Tens of billions of potentially habitable, Earth-size planets in our galaxy

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Re: Tens of billions of potentially habitable, Earth-size planets in our galaxy

#31

Post by danteembermage »

JonSkeptic wrote: post #2

>One in five stars in our galaxy like the Sun have planets about the size of Earth and a surface temperature conducive to life That is a considerable claim that jars with most of the astronomical data I've seen. 1 in 5 is far more probable, perhaps an order of magnitude more probable than I've previously heard. Does anyone have studies that corroborate their claim? [EDIT] Later in the article data is cited that more…

I think a key point is that, unless planets rotate in a plane that nearly osculates our line of sight vector they will not be observed by current methods. Basically any planet whose orbit from our perspective looks like an oval rather than a left-right wobble will not be observed by current methods which check for light flickers as the planets cross their star. There are complex factors at work here, but I'd think a reasonable approximation would be that solar systems plane of rotation are oriented randomly.

So, given random rotation, if we would expect to observe 1 out of 100 plants using this method and then find that there are planets around 1 out of 200, we can extrapolate that (1/100)/(1/200)= 1/2 of suns have planets. That explains the discrepancy anyway; since so many don't rotate in the right plane the fact that we observe them at the frequency we do, rare as it is, means they are in fact quite common. The universe just got a lot more exciting!

Re: Tens of billions of potentially habitable, Earth-size planets in our galaxy

#32

Post by blacksmith_tb »

maglos wrote: post #8
codeboost wrote: post #6

But let's say what we really hope for is true. What if we somehow discover that a large number of these planets are teaming with life ? What then ? How would that help us ? Spiritually, economically ? Wouldn't that make us feel even less significant ? I'm just wondering, why are we hoping there is life out there and what would we do if we find it ?

I think it's more dangerous to seek alien life, spiritually and economically then it is to actually discover it.

Well, SETI isn't free, but it doesn't seem too expensive compared to some of the things we invest resources in. As for the spiritual danger of the seeking, I can't say it seems too fraught - finding, on the other hand, would at least require some adjustments to a few creation myths...

Re: Tens of billions of potentially habitable, Earth-size planets in our galaxy

#33

Post by ceejayoz »

lxmorj wrote: post #30
ceejayoz wrote: post #4

I've seen this reported as 2 ( http://www.theguardian.com/science/2013/nov/04/planets-galax... ) and 8.8 ( http://abcnews.go.com/Technology/wireStory/study-88-billion-... ) billion this week. Anyone know why the wildly different numbers being reported for the same research? I'm also curious about Earth-sized moons around gas giants in the habitable zone.

Don't Earth-sized moons of gas-giants have a few others problems? Less consistent weather patterns due to a more complicated relationship with the sun, stripping of the atmosphere due to gas giants gravity, and crazy huge tidal forces from the same.

I'm not an expert, so take these with a grain of salt.

There are plenty of spots on Earth with unusual weather patterns (not to mention extremophiles). I'm not sure what sorts of weather changes a gas giant moon would see but I'd imagine they're surmountable via evolution.

Titan has a nice atmosphere, so it's possible for a gas giant moon to retain one. Gravitational force diminishes pretty quickly with distance, so if a moon's a reasonable distance from the giant it'll likely be fine there.

Tidal forces give Io troubles, but the other moons of Jupiter seem to be fairly stable geologically.

Re: Tens of billions of potentially habitable, Earth-size planets in our galaxy

#34

Post by codeboost »

marcosdumay wrote: post #22
codeboost wrote: post #6

But let's say what we really hope for is true. What if we somehow discover that a large number of these planets are teaming with life ? What then ? How would that help us ? Spiritually, economically ? Wouldn't that make us feel even less significant ? I'm just wondering, why are we hoping there is life out there and what would we do if we find it ?

Probably, nothing changes untill we start communicating with them, what may take a while. If we start feeling less significant, well, list that in the benefits... But I doubt it'll happen. Rationaly, we should start looking hard for the explanation to Fermi's Paradox. Since it's not in our past, it must be in our future, what's very bad. But we are not rational, so we probably won't.

So we meet the aliens, we communicate with them, we become friends, they share a bunch of technological discoveries with us.. Then what ? We travel some more ?

If we can travel parsecs to meet them, wouldn't we be supremely technologicall advanced ?

I mean, the human race is pretty technologically advanced today, too advanced actually and it's hurting us as much as it's helping.

Will we some day realise that it is of no use to pursue higher mountains or more distant stars, because at the end we're still stuck within ourselves ?

What if the supremely advanced aliens realised this a long time ago and renounced technology all together, because it ended up destroying them ?

I wonder..

Re: Tens of billions of potentially habitable, Earth-size planets in our galaxy

#35

Post by nikcub »

I'm curious as to what is next, now that Kepler is dead what do we do to substantiate this data further?

My impression is that there is not much more we can do to confirm outside of the statistical models giving us probabilities, it would take some much more advanced detection tech (or traveling there) to get further, which means we might be stuck at this point for a little while.

Re: Tens of billions of potentially habitable, Earth-size planets in our galaxy

#36

Post by w_t_payne »

This raises the obvious question .... Where is everybody?

It's like we were born on the Marie Celeste; a place that should clearly be brimming with intelligent life, yet appears (on the face of it) to be an empty desert.

The more we learn that the extent to which the galaxy is chock-a-block with habitable worlds, yet apparently devoid of intelligent life, the more I get a truly creeped-out feeling that we are living in some horror-movie galaxy where something is killing everything.

Re: Tens of billions of potentially habitable, Earth-size planets in our galaxy

#38

Post by [deleted] »

nikcub wrote: post #35

I'm curious as to what is next, now that Kepler is dead what do we do to substantiate this data further? My impression is that there is not much more we can do to confirm outside of the statistical models giving us probabilities, it would take some much more advanced detection tech (or traveling there) to get further, which means we might be stuck at this point for a little while.

[deleted]

Re: Tens of billions of potentially habitable, Earth-size planets in our galaxy

#39

Post by Lambdanaut »

w_t_payne wrote: post #36

This raises the obvious question .... Where is everybody? It's like we were born on the Marie Celeste; a place that should clearly be brimming with intelligent life, yet appears (on the face of it) to be an empty desert. The more we learn that the extent to which the galaxy is chock-a-block with habitable worlds, yet apparently devoid of intelligent life, the more I get a truly creeped-out feeling that we are living…

Perhaps life is common, but sentient space-fairing species aren't

Re: Tens of billions of potentially habitable, Earth-size planets in our galaxy

#40

Post by VladRussian2 »

Diederich wrote: post #13

In my mind, Fermi's Paradox looms very large. http://en.wikipedia.org/wiki/Fermi_paradox

The Fermi paradox is "why a highly developed civilization isn't behaving like a Western colonialists or tourists toward primitive natives of some remote wilderness".
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