Odds against Earth-like planets

http://news.bbc.co.uk/2/hi/science/nature/2701977.stm ^ | January 28, 2003 | Dr David Whitehouse

[Burkeman1]

Oh. I agree with you. My .01 figure was pulled out of thin air. But I believe there are plenty of Earth sized planets out there (with gravity equal to 1 Earth G more or less) that could one day be settled by Humans.

But as to the question if they have even a suitable atmosphere, much less liquid water, much less even primitive life, much less intelligent life- it is statiscally almost impossible. If there is intelligent life out there it is almost certainly in another galaxy and there are billions of galaxies. Humanity will never encounter another intelligent species even if we develop the technology to travel to neighhboring galaxies. I agree- SETI is a waste of time.

[<1/1,000,000th%]

I looked at a bunch of stars. I didn't see any planets either.

[pjd]

Either there's a super-heavy companion in some orbit,...

OK. I agree with you completely now that I understand your point.

[longshadow]

****"If our rather ordinary star and solar system has two,....."*****

See, I'm just a dumb truck driver, but how do you get to "our rather ordinary"?

"Rather ordinary" refers to the word "star," not "solar system."

We've catalogue boat loads of stars, and our sun is very ordinary in comparison to the range of stellar types and sizes out there.... in fact, it's a bit on the puny end of the range.

[PatrickHenry]

We're type M, in the main sequence (yellow color on the chart):

[longshadow]

Hey; nice H-R diagram!

[donh]

The Sun is expected to swallow up this planet in about 5 billion years as it enters the Red Giant phase of life. It will subsequently convulse, and spew the major portion of its mass into space.

Sell short.

[donh]

What the article doesn't state though is that planetary systems without Jupiter like outer planets cannot support advanced life either, because the large Jupiter like gas giants are required to keep catastrophic meteors from impacting any life bearing planets in the habital zone.

Huh? What space science book did you get this from? I disagree with your statement, though as shoemaker-levy showed us, an outer planet can capture an occasional comet/asteroid.

I don't think you're getting the point. A large jupiter-like planet serves as a vacuum sweeper to mop up all the loose chunks of rock in accentric orbits that might eventually slam into a life-bearing inner planet. Leaving only chunks of rock whose orbits are similarly close to circular, such as ours. (And therefore, a great deal less likely to hit us.) This has the effect of greatly reducing the impact hazards on the road. Considering that we came very close to losing all of life on this planet 5 times from known impacts, this is not an inconsiderable service, which must be counted as a major element in assessing the probability of life on a given planet.

[Aracelis]

That's why I think SETI is just a waste of money and perfectly good imagination.

Why does this myth continue to be believed???

SETI uses NO tax-dollars!!!

Now, if you'd like to remove our personal liberties and make it impossible to voluntarily fund SETI or contribute our scientific knowledge to the endeavor, that's a different matter entirely...I think it would be called fascism.

[Magnum44]

I'll see your arguement over the long haul (millions/billions of years). I am not a space/life science guy, just an orbit mechanics and satellite design guy. I only expect to be around for about 8 or 9 jupitor orbits myself. :^)

[PatrickHenry]

Dead thread bump.

[Eaker]

It is alive again as it is quite interesting.

http://www.freerepublic.com/focus/f-bloggers/1646385/posts

[Recovering_Democrat]

May be as rare as an intelligent idea from a Democrat party leader?

BWA HA HA HA HA HA HA HA HA HA HA HA!

[MikefromOhio]

I love how these blanket statements come out when we haven't even discovered 1% of 1% of 1% of the universe yet.

[ChessExpert]

I liked the article and most of the comments. Here is a criticism, perhaps minor, perhaps not:

"The way we are trying to get out of this pessimistic position," says Dr Menou, "is by seeing if Earth-like worlds could form in a planetary system after the inward migration of Jupiter worlds."

Why is this a pessimistic position? Why are we trying to get out of this pessimistic position? This sounds like biased science. How about if he reported that this was an optimistic finding and explained how he was trying to protect this optimistic finding from challenges? Sure, the direction of bias would be different. But would the extent of bias be any different?

How many people have we sent to Africa and elsewhere to prove (biological) evolution? How many have we sent to disprove evolution? Unless those numbers are about the same, we may have had biased science.

I think the ideal is to avoid favorites that you try to prove or disprove. A good scientific environment would have investigators report without concern for fear or favor, and let the chips fall where they may.