Sun's properties not 'fine-tuned' for life

[Pale Blue Dot]

Source: New Scientist

There's nothing special about the Sun that makes it more likely than other stars to host life, a new study shows. The finding adds weight to the idea that alien life should be common throughout the universe.

"The Sun's properties are consistent with it being pulled out at random from the bag of all stars," says Charles Lineweaver from the Australian National University (ANU) in Canberra. "Life does not seem to require anything special in its host star, other than it be close."

Some previous studies of the Sun's vital statistics have concluded that it is unusual among stars, for instance, by having a higher mass than average. Such atypical properties might somehow help explain why the Sun seems to be unique, as far as we know, in having an inhabited planet.

But the earlier studies only looked at a small number of solar features, such as its mass and iron content. Lineweaver suspects there was a temptation to sift through the Sun's properties, then focus on the outstanding ones while ignoring the normal ones.

Read more: http://space.newscientist.com/article/dn13956-suns-properties-not-finetuned-for-life.html?feedId=online-news_rss20

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This is good news for those of us who would like to believe that life is relatively common in our universe.

[dipsydoodle]

1. Not life as we know it Jim

[14thColony]

2. True

I think, should we ever get 'out there' we're going to be stunned at how commonplace life is. As Jeff Goldblum's character says in Jurassic Park, "life finds a way."

[Warpy]

3. The problem will be in recognizing it and, if it communicates,

communicating with it.

Remember, we can't communicate with the other species here except in very rudimentary ways, and we have the same frame of reference. Imagine trying to figure out how to talk to a species on a planet completely unlike ours who might use, say, pheromones.

Whatever it is, we can pretty much guarantee the universe isn't populated by bipedal apes who communicate vocally.

[BobTheSubgenius]

4. I'd hate to think that....

.....this is the best the Universe could do.

[ohio2007]

5. What if this is as good as it gets ? Jack Nicholson ( as good as it gets)

I'd prefer to think we inhabit a back water corner .... the armpit of the universe




http://www.youtube.com/watch?v=6Y9BukEBI9c&feature=related


http://www.youtube.com/watch?v=bOfoeOsvYmU&feature=related

[14thColony]

9. But according to Star Trek their women are hot and speak English!

:) Yes, of course you're correct. Since we don't even have a universally-accepted definition of life for our planet yet, just recognizing non-terrestrial life could be a formidable challenge. It will probably make our view of what constitutes 'life' seem rudimentary at best. As for communication, as you say we can't even do it very well with other (possibly) sentient life on our own planet, so that will be even more of a challenge. At least mathematics based on certain universal constants will be a starting point, once everyone figures out everyone else's mathematical symbology. Of course this assumes we ever even encounter the theoretically half-dozen or so spacefaring civilizations that would exist at any one time in our galaxy. Unless one of them happens to be on a planet around Proxima Centauri I'd bet humankind will be alone for a very long time to come.

[Penance]

6. It's not the sun that's the issue

It's the planet. Earth has a number of nice features that make it habitable by carbon and water-based life forms, like being solid (unlike Jupiter, Saturn, Uranus and Neptune), in a zone where liquid water is common (unlike Europa which is covered in ice), having enough surface water to support life (unlike Io), having a liquid iron core and hence a magnetic field to shield the inhabitants from a lot of EM radiation (unlike Mars) and not having undergone a runaway greenhouse effect (unlike Venus where the surface temperature would melt lead and surface "air" pressure would crush you like a bug). There are a lot of variables and we don't have enough data to say where life can and cannot form. We only know of one inhabited planetary body. Considering that there are hundreds of billions of stars in our galaxy and there are hundreds of billions of galaxies in the universe, it doesn't seem reasonable to assume ours is the only plant to harbor life. On the other hand, we know from our own solar system that life isn't all that common.

[Larkspur]

7. Yep and it took about 4 billion years for life to show up on our planet

The History Channel had a very good documentary on the history of our planet and the geologic journey it took to get life to start on our planet.

[sutz12]

8. I thought they said that life showed up very early...

as long as 3.5 billion yrs ago. Intelligent life may have taken most of the 4 billion years, but early proto-protein molecules and one-celled organisms were forming almost as soon as we had liquid water on the surface, in the first 1-1.5 billion years of our planet's history.

[Tesha]

11. Maybe there was earlier "intelligent" life? ;-)

[14thColony]

10. We're not so sure about our solar system yet.

Remember we've only actually landed on a few bodies so far, and only a couple of the Mars landers were even equipped to attempt to detect life. Landers are being planned for some of the Saturian and Jovian moons, of which Callisto, Ganymede, Europa, and now Titan are thought to have deep liquid oceans. Titan is confirmed to be covered in a soup of organic molecules. Even one of the very large asteroids in the Asteroid Belt is suspected of having a liquid sea under its surface. Mars might just have liquid water flows, at least seasonally. And so far in human experience liquid water invariably equals life.

But even then, all Earth's characteristics prove is that Earth is perfect for exactly the sort of life that evolved here. Well of course it is, because the planet's characteristics forced a type of life adapted for Earth. Somewhere on Europa there might well be a 'fish' swimming around in the ocean there thinking how lucky Europa was, being protected from impacts by Jupiter's gravity, with a thick ice layer to shield it from radiation, and with Jovian tidal forces to keep the ocean liquid. I think if life can get started, it will always find a way. And I think recent evidence suggests it might be hard to PREVENT life from getting started.