Interstellar Space also a Frothing Primordial Soup!

16 07 2010

Image of the anthracene band recently identified in the Perseus star formation region. This molecule is formed by three hexagonal rings of carbon atoms surrounded by hydrogen atoms. Credit: Gaby Perez and Susana Iglesias-Groth

Researchers from the University of Texas and the Astrophysics Institute of Canarias have announced a discovery of yet more evidence that life may be a common, natural result of cosmic processes.  The highly complex organic molecule anthracene has been detected in an interstellar cloud of molecular gas 700 light-years away toward the constellation Perseus.

Anthracene, which is a prebiotic chemical, is found in its oxidized form in aloe and possesses anti-inflammatory properties.  Perhaps more importantly, in the presence of starlight, water, and ammonia, anthracene can form amino acids and other compounds that act as the building blocks of life.

In all, good news for the astrobiologically-inclined.

Alien archeology – now a real science?

15 05 2010

Concept sketch of Mars xenoarchaeological site from movie Total Recall. Credit: Steve Burg

Well, I’ve done it.  Making good on a promise I made to myself while presenting a poster at the Society of American Archaeology conference in 2008, I recently submitted an article to the journal Space Policy outlining a framework for a science that doesn’t quite exist yet: Xenoarchaeology.

“Xeno” is Greek/Latin for “foreign” or “stranger.”

Seriously.  I drew from SETI protocols, interplanetary geological sample return guidelines, archaeology fundamentals, and historical examples to make a call for a proactive set of xenoarchaeological guidelines.  My argument?  -The moment that we find something we think might be the real deal on another planet is the wrong moment to try and figure out how to study it correctly and credibly.  And we’ve got spacecraft and landers everywhere these days.  -It’s only a matter of time until we do cross over something that makes us double-take.

To paraphrase my general points in the paper, an archeological mindset is particularly well-suited to analyzing a site of truly unknown character, but there are planetary science landmines a regular archaeologist would be completely unprepared to dodge.  Gravity, temperature, chemistry, and electromagnetic environment can all be (and likely are) very different on another world, which will affect essentially every property of an object.  On Earth we can take all of those things for granted – the strength and effectiveness of friction, for example.  On Mars?  We had to completely redesign the drill bits used on our Mars rovers simply because the effectiveness of a cutting edge on Mars is only half what it is here on Earth because the atmospheric pressure is so low, which is in turn because the gravity is 1/3 weaker.  See what I mean?

If it walks like an arrowhead, and it talks like an arrowhead… it might not actually be an arrowhead on Mars.

So, that’s my stab at taking a scientific discipline out of the realm of science fiction and elevating it to reality.  -The paper made it favorably through editorial review, and I am waiting to hear back on comments from the peer referees.

My ulterior motive?  I really do believe it’s only a matter of time until we find something – and if I center myself in the burgeoning discipline, when we do find something (if I don’t happen to be the one who stumbles across it, myself)… they’ll have to call me.

Fingers crossed.

(NOTE, 10/2010:  The paper was accepted and published!  Find it here.)

(NOTE, 05/2011: See the follow-up post on article responses here!)

Target: Titan & Silicon-based life

18 03 2010

Move over, Mars.  According to new imagery from the Cassini spacecraft and new research recently published in the Journal of Cosmology, Saturn’s moon Titan may be the hottest exploration ticket in the Solar System.

Titan in front of Saturn. Credit: CICLOPS

Up until only five years ago, the massive moon Titan was one of the last great mysteries in our neighborhood of planets.  Itself bigger than the planet Mercury,  Titan’s freezing (-290 degrees!) smoggy, opaque, nitrogen-and-methane atmosphere was so think that we had no idea what its surface looked like.  It was only after the Cassini spacecraft settled into orbit in 2004 with advanced instruments that we were able to punch through the fog to see what was going on.

Radar images of Titan - dark areas suggest lakes/oceans of methane. Credit: CICLOPS

What we found was staggering.  Coastlines.  Erosion.  The most Earth-like environment to date.  As predicted nearly three decades ago but unproven until recently, Titan is the only other place in the solar system home to a hydrologic cycle of sorts.  I’m talking about lakes, streams, clouds, and rain.  But on Titan it isn’t water raining from the sky and running down mountainsides.  It’s far too cold, and water there is always a solid mineral, like silicon is here on Earth.  Instead, Titan’s “water” is liquid methane.

Utah? Rendering of possible Karst terrain on Titan. Credit: NASA/Malaska

While this is terribly good news for geologists interested in the processes of erosion (geomorphology), it was apparently bad news for hopeful astrobiologists.  Without liquid water, life as we know it can’t exist.  But hold that thought – Researcher Pabulo Rampelotto of Brazil’s Space Research Institute’s Exobiology and Biosphere Laboratory has identified an alternate biological chemistry that might support life on Titan…

Silicon-based Life

Our current understanding of physics, chemistry, and their roles in biology suggest that an organism could survive using an entirely non-carbon-based metabolism.  Silicon is a likely first place to look for alternatives.  Like carbon, (the chemical backbone of life as we know it,) silicon can form four bonds, stable bonds with itself and other elements, and long chemical chains known as silanes, which are very similar to the hydrocarbons essential to life on Earth.  Silicon is more reactive than carbon, which could make it optimal for extremely cold environments.

However, silanes spontaneously burn in the presence of oxygen, so an oxygen atmosphere would be deadly to any silicon-based life, and water as a solvent would be equally deadly for the same reason.  So, any environment with the potential for silicon-based life would have to be very cold, devoid of oxygen and water, but with another compatible solvent, such as liquid methane.  Sound familiar?

Of all places in the Solar System, Titan seems to be the only place active enough for life to currently exist.  -And even though Titan is definitely an alien and hostile place, it looks like we’ve identified a way for life there, as Crichton’s Ian Malcom famously put it, to “find a way.”


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