Scientists Confront 'Weird Life' on Other Worlds

SPACE.com ^ | Friday, May 7, 2004 | Leonard David

[Quix]

I think this is some sort of noise.

For what purpose is hard to guess. Perhaps desensitization toward disclosure of various ET races.

[attiladhun2]

Sulfer-based life? Imagine the BO a Sulferite would give off. Come to think of it, there's some bums who hang around the liquor store near my house that just might be sulfer-based life.

[Pagey]

"Titan is the ‘weirdest’ of planetary bodies in our Solar System -- meaning different from Earth -- possessing hydrocarbon surface bodies and methane rain..." so said Dirk Schulze-Makuch, Assistant Professor in the Department of Geological Sciences at the University of Texas, El Paso.

I wonder why he doesn't talk about 'Europa' and it's 'Icy Crust'. There are many many pictures online from our Galileo spacecraft that what scientists publicly state are ice floes. JPL has photographic proof of two active volcanoes on 'Io' also, with 75 mile high plumes and 400 km long lava flows. Can there possibly be any type of organic life in ice or lava? You'd think so. Point being, the 'smokers' that we've found rising from the floor of our oceans are surrounded by plants and foreign shaped animals we've never seen before. Surely this is within the realm of possibilities elsewhere on other planetary bodies. Now, whether the average human on earth will even entertain that possibility is whole other issue.

[Momaw Nadon]

[Ichneumon]

Because I have no scientific background, I wonder why "carbon based" is the only point of interest. Might'nt there be other bases for life forms?

Well, there are two reasons. The first is that *our* type of life is carbon-based, so we have the most knowledge of that kind -- also we serve as proof that carbaon-based life *is* indeed possible, we're not so certain about any other types.

The second is that carbon is an extremely "versatile" element, capable of combining is so many ways that practically countless different kinds of molecules can be formed from it (thus producing a vast array of molecules that produce the sort of molecular complexity that can make life processes possible. Also carbon makes for molecules that are neither too tightly nor too loosely bound -- molecules that are too tight won't interact easily, and molecules that are too loose will disintegrate spontaneously too often. As far as we know no other element has properties as ideal for life-suitable compounds, although silicon seems to be a decent (although not ideal) second place, and silicon-based life seems to be at least a possibility.

However, even looking at only *chemical* based life may be too restrictive. For all we know life may be possible based on nuclear processes under the right conditions (like inside the sun), or who knows what else.

[Major_Risktaker]

I'll stick to CARBON BASE LIFE in this UNIVERSE for now!

[Lester Moore]

God, Who is and will always Be a mystery, may have several earth-like experiments going on in the vastness of the endless universe.

What would an omniscient, omnipotent, omnipresent God be ascertaining?

If that is true, my open mind tells me they are far enough apart that they will never know the existence of the others.

How does your open mind tell you that this is so?

[furball4paws]

People like to speculate about Si based life forms and even throw around S, B and Ge. However, the chemistry of these elements makes then very unlikely as a basis for life. Carbon is the only element that forms complex stable molecules and easily forms compounds with heteroatoms (N, O, P, S, Se, Fe, Mn, Co, Zn, Ni, Mo, W and even Cl, Br and I. These are required to get a great enough variety for the many chemical reactions required for living systems.

We might find non-DNA/RNA based life and even life forms that do not make or contain lipids, carbohydrates or proteins, but it is extremely unlikely to find non carbon based life.

Since most stars probably have planetay systems, the chance that there is life out there is extremely high, the probability is probably 1.0. I would be glad to be it is carbon based and I would be happy to bet it won't look like me (egad, I hope it won't).

[Junior]

Carbon is popular because it has so many "attachment points," making for large numbers of chemical combinations. I don't think helium or copper have that many (though the latter could take the place of iron in osygen-dependent systems).

[Reeses]

it is extremely unlikely to find non carbon based life.

Depending on how broadly you define life, it could be argued that it's already right in front of you, or at least the precursors of non-carbon life. Computers have nervous systems, respond to stimuli, make decisions. They can't reproduce without us yet, though they are so complex that we can't build them without their help. They don't have free will, consciousness, or self awareness yet, but neither does a potted plant which is considered alive.

At some point, artificial life ceases to be artificial.

[Maven]

A blade of grass is a life form. At some point computers will have to be included as well. What's cool about that is we are their God. Will they worship us someday or be embarrassed?

They'll allow all computers to worship us, but mention of us won't be allowed anywhere in public....

Maven

[longshadow]

Zeus-like placemarker

[Darksheare]

And for some reason I'm thinking lithium or magnesium..
*shaking head*
Moving lichen like creatures that explode in the rain!

[furball4paws]

Be careful about those potted plants!

Audrey II is waiting for you.

[dr_who_2]

A. C. Clark's "Report on Planet 3" was a fun read. I've never heard any serious scientific argument for/against the possibility of non-organic lifeforms. Any opinionated chemists out there?

[dr_who_2]

True, but that means we'd only consume them in the necessary trace amounts.

[dr_who_2]

Remember when Dr. Hawking made himself look pretty goofy by suggesting that computer viruses were a form of life? How many lines of code would it take to make a self-adapting virus? Even then, how easy would it be for us to be able to stop it? Pretty easily, actually. Sure, there's a chance that some goofball has a virus from 1994 on their computer somewhere, but it will have a limited lifespan nevertheless. Sooner or later, someone is going to power down the machine, wipe the hard drive, and trash the computer. No one has designed a virus that can get over that hurdle without the help of humans. It's much easier ( or more attractive to your average cracker) to design a virus that kill itself (ie, one that can bring down a network, attack a power grid, reformat a hard drive). It doesn't matter if all the computers out there have buggy tcp/ip stacks and run windows. I'm not saying if my fractal screensaver suddenly became self-aware, I wouldn't be impressed. We just aren't there yet. We may never be.

As for diseases, cattle, etc, we're getting more efficient at doing what we've been more or less doing for centuries. But is this really "artificial" life we're talking about here? Going back to programming, if I had working source code for any program, I could probably tweak it in all sorts of superficial ways. Doesn't mean that I could write the same thing from scratch. The big difference there is that many could.

[van_erwin]

LOL. Got any photos? What kind of freakshow? Why do you live near that?

[Cronos]

Just because life on earth is carbon based doesn't mean life elswhere can't be copper or helium based.

Err... no, that's not possible. Copper doesn't have the ability to "combine" with other elements in such wide varieties as Carbon does. And as for Helium, duuuuuh, it IS an inert gas (like Argon, neon etc.) : inert meaning you can't really get it to combine with anything else very easily.

On the opposite end of the scale you have hydrogen and the group containing fluorine, iodine etc. that combine with pretty much anything very quickly.

Carbon combines quickly providing energy transmission -- hence we use Carbon bases to create plastics. Carbon is smack dab between those two (Inert elements and highly reactive elements) and has the second lowest atomic number in its "family", and the ones with higher atomic number won't combine so easily as they have so many more electrons, protons etc. The only exception to this is silicon, so a silicon based lifeform is well within the realms of possibility. Lifeforms based on other elements(bar the inert elements like helium) may be possible under extremely unusual circumstances.

[Cronos]

Think of it this way -- life exists where water is liquid, not gaseous (vapour) or solid (ice) and that's only between 0C and 100 C (273 and 373 K)