Millions of Earths? Talk causes a stir

[n2doc]

Alan Boyle writes: A leader of the Kepler planet-hunting team has created a slow-moving scientific stir by telling an audience at a high-tech conference that our galaxy could harbor 100 million Earths, based on the space mission's raw data. The resulting buzz focuses not only on the findings, but also on the means by which they came to light.

The conclusions drawn by Harvard astronomer Dimitar Sasselov totally make sense, based on the composition of our own solar system. If we look at the eight dominant planets, four of them are Earth-scale, two are Neptune-scale, and the other two are big gas giants. (And then there are hundreds or thousands of smaller worlds like Pluto.)

During his July 16 talk at the TEDGlobal conference at Oxford, Sasselov observed that the preliminary results from Kepler were following that pattern. So far, planetary candidates "like Earth" - those that are no more than twice as wide as our own planet - make up the largest category in Kepler's database, according to a chart Sasselov used to illustrate his talk. The proportion is significantly more than that for Neptune-sized, Saturn-sized or Jupiter-sized candidates. (These observations came just after the eight-minute mark in the video embedded above.)

"The statistical result is that planets like our own Earth are out there," Sasselov, a co-investigator for the $600 million Kepler mission, observed. "Our Milky Way galaxy is rich in this kind of planet."
If you extrapolate that kind of distribution to the entire Milky Way galaxy, there might be 100 million alien Earths out there, Sasselov said.

more
http://cosmiclog.msnbc.msn.com/_news/2010/07/26/4756559-millions-of-earths-talk-causes-a-stir


This slide from Dimitar Sasselov's presentation shows the distribution of Kepler planetary candidates by size. The largest category comprises candidates "like Earth" in size, with radii less than two times Earth's radius (<2Re).

[izquierdista]

1. What do they all have in common?

Jesus has a personal relationship with the "chosen people" on every single one of them!

[rurallib]

4. which explains why Jesus hasn't come back

33 years at each of a million earths. And that is just one galaxy.

[MineralMan]

5. Jebus is busy at the moment, and can't take your prayer. Your

prayer is very important to Jebus. Please continue to hold. Estimated holding time is 2 million years.

[Ichingcarpenter]

2. If their Sun is a million or a billion years older than ours

And has intelligent life. Imagine what a billion or millions of years would do to an evolutionary head start in intelligent life.

[meow mix]

6. wonder what they can tell about our planet... by looking thru a device

our sensors could be primitive in comparision, of course.

[Ichingcarpenter]

7. At a million or billion years ahead

They would look and talk to us like we do to the earth worm (billion) or a pet iguana (million).

Perhaps we are part of a computer simulation for them if they exist.

[Statistical]

9. Depends on how far away they are.

If they are say 10,000 light year away even if they could see earth perfectly they would be seeing earth as it looked around 8,000 BC.

[murray hill farm]

13. and they would be many more light years than 10,000 away.

as far as we know, the speed of light is constant. It is more likely, no matter how adanced their technology might be, they would still see the earth as it was millions of years ago...and say to themselves (if such beings did exist) "nothing there..move on".

[sui generis]

3. that's very cool. I wonder what their relative age is

AND are they in their orbital life zones and do they have the same geomagnetic and atmospheric properties that shield us from solar radiation in this solar system?

DNA is fragile stuff, as would any protein signalling method based on amino acids and sugars. The other important Fermi-esque question is where are they on their evolutionary timelines? There may be 100 million but are any of them close enough in proximity and time and development to have species capable of engaging in communication much less able to engage in mutual discovery?

[Statistical]

10. Exactly all those things narrow the field down by orders of magnitude.

However that is why it is a good sign that "earth sized" objects are relatively common. Because 99% of them will not be in a location that is supportive of life. Decades, maybe centuries more research is needed but this is a very good first sign.

If earth like planets were very rare (say 1 out of 10,000 planets observed) that would bode poorly for the probability than these very rare planets also ended up in the very rare set of circumstances to develop life.

[qazplm]

14. I'm not sure it is established

that the set of circumstances to create life is "very rare."

Extremephiles alone would seem to indicate that life can exist in a very wide swath of environments.

If you are speaking of complex, Earth-like life, then certainly it becomes rarer but we are still talking about a temperature range of well over 100 degrees F which isn't all that narrow for Earth-like life with Oxygen, Hydrogen and Carbon being the main building blocks and all three being pretty common throughout the universe.

Certainly, there are other limitations, you'd like a magnetic field and you'd like at least one companion to keep the planet steady and you'd like it to be in the Goldilocks zone. But I don't think any of those things are necessarily so rare as to be called "very rare."

I personally believe it almost inevitable that there is life out there in this galaxy. I don't know whether it is more advanced than us, or if we are the current apex or something in between. But 1000 years from now, were I to somehow live that long, I think the odds of me seeing mankind living on a planet in another solar system are astronomically high.

[Statistical]

15. On a long enough timeline mankind will either live on planets orbiting distant stars....

or go extinct.

I would like to think the former is true.

[roguevalley]

17. then again, if you are talking about life like us, maybe you have

a point but the idea that life is rare because life is us is ethnocentric. Not that I am saying you are but this view that life is like us in the goldilocks zone is limiting.

[FiveGoodMen]

18. And the crazy thing is that scientists seem to fall for that

(Either that or it's just consistently bad reporting, which is possible)

Anyway, every time I hear a scientist quoted saying that life needs exactly earth's conditions to exist I think, "Well, there's a guy in the wrong line of work!"

[badgerpup]

8. Cool...

Life can be very stubborn and tenacious...I'm assuming there's a kind of life on these Earth-type planets.

But then I read a lot of science fiction- so the concept is not frightening to me but happy-making.

:bounce:

[Myrina]

11. Can we figure out which one the Progressive Liberals live on pelase?

I'd like to apply for refugee status and eventually, citizenship. Thanks ~

[Ichingcarpenter]

12. They don't take Pets

which is what you would be to some of them........

I saw the sign from my telescope.

LOL

[Vinnie From Indy]

16. It would seem a statistical cinch that there are a very large number of planets

in our galaxy that are in the Goldilocks zone and have the other essentials like a magnetosphere to shield the planet from the solar wind etc. What I find fascinating to contemplate is the possibility that the theory "survival of the fittest" is a constant in regard to the development of intelligent life forms wherever they may be found in the universe. If that is the case, a strong argument can be made that it is probable that any life form we may encounter or that encounters us might not necessarily be friendly.