NASA scientists recently briefed the White House on a discovery made by the Phoenix lander. The blogosphere and editorial pages across the Western world were rife with speculation–had life been discovered? Was there the potential for life? Was there evidence (through spectroscopic analysis) of complex organic molecules?
In the end, it was the discovery of perchlorate that was supposedly so momentous.
Perchlorate is an anion with four oxygen atoms and one chlorine atom. The chlorine atom has an oxidation state of +7 in order to accommodate the the demands of bonding to the oxygen atoms. Despite its high oxidation state, it is actually quite stable due to two things–one is that in that oxidation state with four oxygen atoms, the chlorine is considered to be a “closed shell,” which lends stability to an otherwise potentially unstable species. The other is that the perchlorate is likely stabilized by several “resonance” forms, in which the the electron density of the covalent bonds is distributed more or less equally across the entire molecule.
Perchlorate is typically formed in areas devoid of water that have a high salt content, such as deserts or dry lake beds. It can be formed industrially by reacting chlorine gas with a strong base. Perchlorate can be used in rocket fuel and fireworks, due to its high oxidation potential and its relative stability. My first thought when I heard the the Phoenix lander had found perchlorate was that somehow, the lander had contaminated the sample site. However, NASA claims that the Phoenix lander used a pure hydrazine fuel (two amine groups linked by a single N-N bond), which rules out contamination.
Are the conditions proper for the spontaneous formation of perchlorate? At this point, further laboratory tests are needed to verify that the conditions on the Martian surface are correct. There is evidence that this can happen on Earth, but given the wildly different levels of temperature, pressure, and UV exposure, I would feel more comfortable with results which illustrated the formation of the anions.
A strong oxidizing compound isn’t always good news for species struggling to survive, but there is at least one example that I could find that shows that perchlorate could be used as an energy source for a bacteria-like organism. Again, given the harsh conditions on the surface, I’m not sure how much this could be true.
At this point, no one can say anything for sure, aside from two facts:
- There is water in the regolith on Mars. NASA cannot accurately quantify the amount. At best, all they can do is guess. Anyone that tries to provide a quantity here is acting with insufficient data.
- There is the presence of a compound that could act as an energy source, but this is atypical of life as we know it.
This brings up my last point, in that we are anthropomorphizing our search for life. Who says that life has to operate according to our known parameters? There may be a completely different way of energy acquisition and waste processing that we can’t even fathom because we’ve been so blinded by our evolutionary history and mechanisms of energy production. I’m completely for the search for “life as we know it,” but I feel as though we should be prepared mentally for “life as we don’t know it.” Too often, we’ve been blinded by our own preconceptions that we miss the answers that are right in front of our collective faces. I’d hate to see that happen now.
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Not to knock this way off the original point, but I’ve notice our mainstream sci fi shows all have that ‘humanocentric’ view. Just about any alien race portrayed is a biped with funny head ridges or skin color… That just seems to be the way most people view scifi… (Although some scifi authors are the notable exception.)
Sorry, please return to the topic at hand…
‘Perchlorate can be used in rocket fuel and fireworks, due to its high oxidation potential and its relative stability.’
Fireworks on Mars? Cool… Ah, sorry, did it again. I’ll stop now…
Life on Earth comes in a myriad of forms other than bipedal (I believe that Phylum Arthropoda, Class Insecta is the most plentiful group in the Animal Kingdom), and almost unending variations… but all dependent upon carbon and water… and most dependent upon oxygen or carbon dioxide.
Assuming we retain a carbon-based form of life, but alter the means of respiration, energy consumption, and reproduction through the use of different elements/molecules, could such a life form develop and what would it look like (how would it operate)? For years scientists believed that no life could exist in the deep ocean that was not directly or indirectly dependent upon light/photosynthesis. However, whole colonies of many different creatures (tube worms, shrimp, mussels, etc.) were discovered to be living around thermal vents with their existence centered upon bacteria that convert hydrogen sulphide into food.
Below the thunders of the upper deep;
Far, far beneath in the abysmal sea,
His ancient, dreamless, uninvaded sleep
The Kraken sleepeth: faintest sunlights flee
About his shadowy sides: above him swell
Huge sponges of millennial growth and height;
And far away into the sickly light,
From many a wondrous grot and secret cell
Unnumbered and enormous polypi
Winnow with giant arms the slumbering green.
There hath he lain for ages and will lie
Battening upon huge sea-worms in his sleep,
Until the latter fire shall heat the deep;
Then once by man and angels to be seen,
In roaring he shall rise and on the surface die.
by L. Ron Hubbard
Yeah, that’s how I felt after I read Dianetics…
Dianetics was actualy written by Tennyson…
Wow ! You actually read dianetics? Don’t think I ever knew anyone who made it thru that crap.
I opted out of Dianetics and read the Celestine Prophecy.
I read both… then wiped, dropped, and flushed. Celestine Prophecy wasn’t bad, but it just didn’t grab or appeal to me viscerally. Dianetics really confused me, as I didn’t realize that it wasn’t a story at first. I thought it was a strange other-worldly culture that was being described in a unique way (without a plot or characters). I guess it really is a strange other-worldly (or parallel universe) culture… and by the time I figured out that I had wasted my time, I decided to go back to reading myths with some semblance of class and style (that were infinitely more believable)… Edith Hamilton’s “Mythology” (Greco-Roman myths with a smattering of Celtic ones too) as well as H.P. Lovecraft’s short stories of horror and woe.
But back to the original subject… Pete, I think our anthropomorphism concerns not extra-terrestrial life in general, but our expectations for SENTIENT extra-terrestrial life. It seems that only space monsters break out of the public imagination for bipedal, anthropomorphic life… the blob, the thing, the aliens from “Alien”, etc. I believe that we want to believe that there is some sentient anthropomorphic life-form out there to relieve a sense of being alone in the universe and perhaps that there is someone (not just something) out there who is just like (or very similar to) me. Collectively we are looking for a connection… hoping to peer into the galactic looking-glass and see ourselves reflected there.
Excellent post/thread. Hollywood’s obsession with extra-terrestrial life is more associated with their needs for a story antagonist than a deep seated need for intergalactic company. Nazis, communists, aliens, terrorists…