Kepler Analysis Projects One-Third of Sun-Like Stars Have an Earth-Like Planet Orbiting

[n2doc]

By Clay Dillow Posted 09.28.2011 at 2:57 pm

One of the fun things about astronomy is that we can only know so much through empirical observation, yet we can “know” so much more through enlightened, mathematical guesswork. Such is the nature of the most interesting new science paper I’ve come across on the Internet today. In it, Wesley Traub of CalTech crunches some Kepler data and makes a tantalizing mathematical prediction: one-third of sun-like stars have at least one earth-like terrestrial planet orbiting in their habitable zones.

If that turns out to be the case, that’s big news of course. The habitable zone, or the “goldilocks zone” as it’s often known (not to close to the star, not too far away), is the orbital range where it’s possible for liquid water to exist. Thus, it’s the range where life as we know it could feasibly take root.

The planet-hunting Kepler observatory is designed specifically to seek out planets orbiting distant stars, and thus far its been a boon for exoplanetary science. In 136 days it has scanned some 150,000 target stars looking for the signature wobble exerted on those stars by orbiting satellites. In doing so, it has found 1,235 potential planets.

It’s from that data that Traub has extracted his conclusion. He looked particularly at the stars that are most like our sun--those classified F, G, or K. He then looked at the kinds of planets that are most often found orbiting them and at what ranges they orbit. In his analysis, he notes many interesting (and somewhat expected) things, like the fact that nearly a third of the planets Kepler has found orbit their stars in less than 42 days, putting them too close to be in the habitable zone (this is also because planets closer to their stars are easier for Kepler to see).

more
http://www.popsci.com/technology/article/2011-09/kepler-analysis-projects-one-third-sun-stars-have-earth-planet-orbiting

[ChairmanAgnostic]

1. If only 1/3 of those planetary systems have spawned

Koch-based life forms, we are in deep shit.

It would be a wondrous thing to learn that we are not alone. Of course, there'd be some problems, too.

a) The NeoCon/Tea Bagger crowd would demand their eradication as a threat to our way of life.

b) Some religious leaders would call them the spawn of the devil.

c) Sheeple who follow either or both of the above would become suicidal, given how their perceived universe suddenly collapsed and fell around their ankles. Given their ability to reason, spell, and read, these sheeple's suicide attempts would mostly fail. This would leave a fairly significant, but small, percentage of the population causing themselves enough harm and damage, that we would be required to provide them with care taking, nursing, and serious support structures, because their suicide attempts would be so badly bungled.

d) The difference in technology would be scary. The fact that they have the ability to contact us means that theirs is far superior to ours. Given the GOP's anti-science approach to the world, it would be nearly impossible for us to even try to close the gap.

e) Given the bald fact that they survived their own self-destructive and war-like tendencies enough to travel and visit alien worlds like ours, it also means that their society has progressed far more than ours. No anti-science Dark Ages (1100 CE - 1600 CE), no war based on philosophies and greed (WWI, WWII, our Iraqi invasion, etc) and no legislation like that of Texas, Okla., Penn, S. Car. and more, which prevents scientific growth and research. Their society would be so far advanced over our "civilization" that we would appear to be little more than short-sighted, war-like, dangerous neanderthals, laughable, pathetic, and potentially dangerous.

[phantom power]

2. It's pretty cool to have some experimental data to plug into Drake's equation

:thumbsup:

[bananas]

3. That's what I was thinking - and the down side, the Fermi Paradox. nt

edit to add Carl Sagan on the Drake Equation: http://www.youtube.com/watch?v=0Ztl8CG3Sys

edit to add that Martin Hellman estimates the failure rate of nuclear deterrence at 1% per year,
so advanced civilizations might only last about 100 years: http://www.nuclearrisk.org/

[pokerfan]

4. Where is Everybody?

Good book...

Fifty Solutions to the Fermi Paradox by Stephen Webb

http://www.thespacereview.com/article/810/1
http://astrobioloblog.wordpress.com/2011/01/09/review-stephen-webb-where-is-everybody

[phantom power]

5. I read some articles proposing that earth's moon has been very important...

in stabilizing our inclination. I think this is yet another factor lacking experimental data, but everything I've seen suggests that the circumstances required to give an earth-like planet a nice big moon are rare.

An otherwise-ideal earth-like planet with no moon would probably have life, but with a highly variable inclination to the sun, it's climate might be too unstable for complex life and/or tool-monkeys to evolve.

As successful as Kepler has been, there's still so many questions we've got nothing but guesses for.
:(

[Phoonzang]

6. There have been several recent studies that say a large moon isn't necessary

for a stable axial tilt (if that's the correct term). Other planets in a solar system would have a stabilizing effect on a planet. So...good news on that front.

http://news.sciencemag.org/sciencenow/2011/05/who-needs-a-moon.html?ref=hp

[txlibdem]

7. Thanks for posting, very interesting thought experiments possible

Here's a list of the nearest stars and their type showing that more than a couple of stars may be suitable, one is 10 light years distant, the other 12 ly distant. Plus a couple of possible at around 20 light years distant.

http://www.atlasoftheuniverse.com/nearstar.html