Astronomers Look for Potential Life Zones

js7a writes "An Australian team of astronomers has an article in the latest edition Science describing a 'Galactic Habitable Zone,' which contains about 10% of all the Milky Way's stars including the Sun. Stars within this band are likely to have rocky planets large enough to hold atmospheres, are sufficiently distant from supernovae, and have existed for at least four billion years. They haven't actually found any life or earth-like planets yet, but presumably this zone is a reasonable place to narrow such searches."

Comments

No life?

[FesterDaFelcher]

They haven't actually found any life

That's good, because I'd be pissed if they had and I hadn't heard about it.

More like....

[Sevn]

Life "as we know it" zone. Someone is going to totally flip the first time they step on a talking rock while mining some nanotube ingredients on some distant heavenly object in the "no life" zone.

Re:More like....

[ApharmdB]

That is only if they recognize that the rock is "talking". Who says it will communicate in any way that humans would recognize as communication? Wasn't fuel in the first Starflight game a crystalline lifeform that no one knew was alive?

Re:More like....

[TrueBuckeye]

Very true, but I guess we have to start by searching for what we understand.
The better question is, how do you define life?

Re:More like....

[Lars T.]

Make sure that those ingredients are not her children.

Re:More like....

[thelexx]

I remember reading about (Sagan is ringing a bell in my head for some reason on this) a gathering involving various biological and astronomical experts that happened some years ago, and one of the questions they kicked around was, "If life evolved elsewhere under non-earthlike conditions, what would be its most likely form?" One of their conclusions was that any such life form would be extremely difficult for us to identify _as_ a life form to begin with.

SETI.

[jabberjaw]

First I am not affiliated with SETI and I am not a radio astronomer. However those of you wondering, these area's will most likely add these zones to the zones currently scanned by Project Phoenix . It would be rather foolish of them not to, no?

Missing the forest for the trees

[mhw25]

I would think of classifying and concentrating our efforts on such a zone can be a little too presumptuous.

Imagine someone said 30 years ago that life is likely to be found on "terrestial planets" and we should concentrate on such and convinced key decisions makers about it: There would be no Pioneers 10 and 11, no Voyagers 1 and 2, no Galileo and no Cassini, and no one would be bold enough to even propose JIMO; and we would have no idea on the existance of "a little solar system in the solar system" in the form of the Jovian moons, and we would not have come to speculate that currently, the most likely site in our neighbourhood to find some form of life outside Earth is on the moon Europa.

Just concentrating on finding "live as we know it" might mean we may miss something right in front of our noses. Somehow it makes me think of those floating jellyfish like creature living on a habitable zone (for them, at least) at some depth on a gas giant that Dan Simmons wrote about in the Endymion books... and that real extraterrestial life, if it exists, may take forms more exotic than even what our imaginations can create. Keep an open mind, and two open eyes.

Missing the facts for the theories

[Eevee]

Well, 30 years ago people did say that life was likely to be found on "terrestial planets." That's why the Viking missions to Mars had experiments to try to detect life--and why the Voyager and Pioneer missions didn't.

Now, if we have a near-infinite amount of resources, then narrowing the choices down is silly. But, as you might suspect, if we have a very limited amount of resources--and you'd better believe time on the large telescopes is pretty scarce--then trying to use that small amount of resources on the best canidates is sensible.

Re:Missing the facts for the theories

[mhw25]

The preoccupation about Mars is exactly the sort of thing that we should avoid - missions after countless missions and inconclusive results at best; and at its worse it spawned those drivels people write about on enterprisemission.com. It may be the second closest planet, conveniently so, arguably Earthlike - and that is the problem - we go there looking only for Earthlike life forms. Not that I'm saying we should not be bothered with Mars anymore, but since we spending so much money going there we shouldn't only be thinking the only form of life to expect is the complex hydrocarbon based, water dependent ones that we know.

I know what you mean, telescope time can be really, in the spirit of the moment, precioussss. Actually getting time to do any experiment on any piece of expensive equipments from academics can be very frustrating. Kind of resulting in what those SETI people do at Arecibo - stick a receiver and whatever people are looking at, record and analyse it - when you have telescope time you follow your hit list, but be prepared, in case you lucky when you are not expecting it.

Re:Missing the facts for the theories

[Daetrin]

You are claiming that we shouldn't focus on Mars or on _any_ place where we think we're most likely to encounter life, yet your previous post seemed to indicate you think we should focus on Europa because you say that's the most likely place to encounter life that we've found.

If we just picked some place at random on the theory that we shouldn't focus on the place where we might expect life, we'd probably end up sending probes to someplace like Charon, which is an extremely unlikely place to find life.

We're doing what's inteligent, we're spending the most effort where we expect the greatest return for the smallest investment, while doing a survey of the rest. Mars is close and relatively easy to get to, and it's a relatively familiar enviroment that we have some idea of how to deal with, which makes missions there comparitively cheap. Meanwhile they're making plans for further missions to Europa and other places that seemed interesting after the first few passes, what more do you want? We don't have enough resources to thoroughly explore _everywhere_ at once, and picking sites randomly would most likely be a waste.

And as to the types of lifeform they're looking for, they tried to make the tests as general as possible. Yes, they were looking for stuff metabolizing certain chemicals, but what else would you suggest? That's the simplest characteristic of life that we can think of. There might be some kind of life that we aren't expecting that doesn't metabolize or doesn't metabolize chemicals that we would expect, but how do you think we should test for that? There's certainly not room on any mission we're going to send in the near future to include tests for all the millions of combinations of chemicals or whatever that could possibly indicate life. We could start to do that if we actually had a colony at the location, but if we found life that wasn't based on any system like earth's, then we might not recognize it even if it was right under our nose.

And inconclusive results just mean that we should study those results and try to figure out what they mean and figure out better tests. Perhaps those inconvlusive results indicate the presence of one of those non-hydrocarbons based lifeforms you're proposing.

Re:Missing the facts for the theories

[mhw25]

I'm not saying that we should not be focusing on Mars. It is conveniently close, as I said, and considering what people say when looking at that old, boring, disproved "face on Mars" at Cydonia - sending something like Surveyor which did and beaming back new photos to discredit that crazy old theory alone was worth the price of the entire mission - almost like "showing the better photos to the believers and seeing their reaction - priceless". And the Vikings did present some questions worth of answering once and for all.

What I was saying is that we should not be too preoccupied by it alone. Keeping in topic, if we start producing, at exponential rate - as Prof Hawkings observed - scientific journals; some of them like these kind of "habitable zones" thingy, sooner or later people, and more importantly policy makers do get into the preoccupied mode - a tunnel vision - and losing the greater picture at the periphery.

There has been two scores of missions to Mars. Jupiter, despite the complexity - was only visited by 3 crafts (2 Voyagers and Galileo), Saturn 2, Neptune and Uranus - once, and Pluto and beyond - sadly none. We are talking about an order of magnitude difference here.

The thing about Europa is that it is the place many people think to find life outside Earth, at this moment and we know that only because we had the sense to look and poke beyond the most likely targets - Mars, Mars and Mars. Cassini may find if Titan or any other Saturnian moon may be as interesting... but we will not know about the Neptunian and Uraninan moons.

I would say we should boldy explore forward... what are we doing, as humanity is that betting on only Cassini to Saturn, forgetting the rest of the Solar System beyond Mars and are very happy that somehow, against all odds, we still have Pioneers 10, Voyager 1 & 2 leaving the solar system - almost like basking in past glories - those were launched a generation ago, before the internet was unleashed on the general public. When will a man made ship pass Pluto's orbit again? When will we try to look at the Kuipers belt, if there is an Oort cloud, or try to find the termination shock? If we don't have the vision to think of going there - because it is not the most likely place to find life, as we know it-, what is the chances of securing the funding, the resources, the inspired commitment of scientists and engineers to propose, design and fight for the means to get there?

Don't get me wrong. I'm not against the search for extreterrestial life form - just had my SETI 4th anniversary and currently beta testing BOINC. But the search for life is only a small part of exploration of the universe as a whole, and rightly so. For if it is out there, and when we have explored far enough, long enough, no matter what form they take - we will find it.

Cool

[Bob Vila's Hammer]

Dr Lineweaver, a research astronomer at the University of NSW...

There is a University of Not Safe for Work? And furthermore, there are doctors working there? Sweet mother of pr0nage!

A Fire upon the Deep- Nice guess!

[ControlFreal]

It is nice to see that sometimes SF authors, maybe by accident, invent some pretty accurate ideas...

Case in point here is the book A Fire upon the Deep[1] by Vernor Vinge. The book describes our Milkyway galaxy at least 30,000 years in the future. The galaxy is divided into a number of concentric zones (the zones of thought): the Unthinking Depths, in which no intelligent life is possible, the Slow Zone, in which only moderately intelligent life such as ourselves is possible, and after that the Beyond and Transcent.

The first two zones seem to pretty accurately be fitted by the results in the article. I do not know where Vinge originally got his ideas, but it's a nice match anyway.

In Vinge's outer two zones, the Beyond and the Transcent, additional nice tricks such as faster-than-light travel are possible. Personally, I can highly recomment this book: it is well written hard technological SF.

[1] A Fire upon the Deep.

Completely different attitudes.

[Eevee]

and inconclusive results at best

That's the reason I want us to go back. If you get weird results, you shouldn't shrug and go on to the next planet; you should find out exactly why the weird results happened. (That is, without interrupting any work for current missions, missing any favorable planetary alignments, totally blowing the budget, or rushing off without careful planning of how to avoid the ambiguous results with the next mission.)

Re:Completely different attitudes.

[mhw25]

I agree with you, totally, about returning to Mars - just not at the expense of other worthy goals.

That is, without interrupting any work for current missions, missing any favorable planetary alignments, totally blowing the budget, or rushing off without careful planning of how to avoid the ambiguous results with the next mission.

Unfortunately that is not what the "political masters" realised. Congress shifting fundings around missions as the political wind shifts. Suddenly the good idea of the International Space Station turned from an orbiting laboratory to a funding black hole, eating almost every morsels that NASA get in the current political climate. Whatever left get directed mostly at Mars. The Pluto Kuiper Express got cancelled, and when the protests came we get a promise of another, scaled down, delayed proposal. Suffering the same fate was the "Deep Space" series of New Millenium Programme that NASA started - and that was even after the spectacular sucesses of Deep Space 1.

The last thing we need to throw at the politicos is a new bunch of contradicting "this is where we should be looking at" documents - lest the start another round of their favourite shifting the funds around game, every shift wasting a few work-in-progress projects, leaving humanity stuck at low Earth orbit and diverting our eyes with periodic hyped up stories about Mars.

What we need to do is continuing looking, exploring outwards, with eyes wide open and not let "tunnel vision" blind us to what would be obvious otherwise.

The meaning of Life

[Doc Ruby]

"Life" is a slippery term, as it was invented and acquired its complelx meaning before science was an organizing principle of our culture. On Slashdot, many of our readers wouldn't recognize a "Life" if they had one :). Meanwhile, intelligence is relatively straightforward to recognize: it is a model of its external environment, in an information feedback relationship with the environment. If that model includes, in turn, a model of the model, that's consciousness. If that conscious model includes a model of its consciousness, that's selfawareness (implying a "self"). And if that selfawareness includes a model of itself, that's starting to resemble a human psyche.

What we want to find elsewhere in the Universe is Intelligence. Intelligence we can communicate with. Otherwise, who cares? Intelligence without communication is an ent falling in a forest with no one to hear. SETI's search for communications signals is sensible, because we're interested in a signaling partner. When we find one, it will think differently than us, unless there's some common intelligence ancestor, or a surprisingly constrained selection criterion for intelligence development. Every possible combination of feedback paths through the multilayered models of intelligence offers a different way of intelligence. Once we find each other, the important question will become how to live together.

Doo, Doo, Doo, Looking out our back door...

[JoeCommodore]

Every time I read articles like this I think of Earth as some crazy old coot who has boarded himself up in his house and peeks through the boards to see if anyone is out there, and if there is, he's gonna yell "go away" and then threaten to shoot em!