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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."
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.
For every annoying gentoo user, are three even more annoying anti-gentoo crybabies. Take Yosh from #Gimp for example.
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.
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.
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.)
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.
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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.