(Visited 40 times, 1 visits today)FacebookTwitterPinterestSave分享0 Don’t expect the “building blocks of life” to last very long on Mars.What’s happened in the 9 years since Dr. Pascale Ehrenfreund radiated amino acids under simulated Martian conditions and destroyed them within hours? (1/28/05). Confirmation of the same, that’s what. In a new paper in Icarus, a team in Switzerland tried a similar experiment, with similar results.The search for organic carbon at the surface of Mars, as clues of past habitability or remnants of life, is a major science goal of Mars’ exploration. Understanding the chemical evolution of organic molecules under current martian environmental conditions is essential to support the analyses performed in situ. What molecule can be preserved? What is the timescale of organic evolution at the surface? This paper presents the results of laboratory investigations dedicated to monitor the evolution of organic molecules when submitted to simulated Mars surface ultraviolet radiation (190–400 nm), mean temperature (218 ± 2 K) and pressure (6 ± 1 mbar) conditions.This is important, they just said. It’s a major goal of Mars exploration. Experiments are important for understanding, they preached. So, practicing what they preach, they irradiated “glycine, urea, adenine and chrysene” (along with mellitic trianhydride to follow up on previous work), using a specially designed Martian simulation chamber. What happened? Bad news; destruction within hours or days for most; a few months for some.The results show that solid layers of the studied molecules have half-lives of 10–103 h at the surface of Mars, when exposed directly to martian UV radiation.By cheating a little, they could imagine some molecules surviving longer. Whether those would be available for the origin of life, though, sounds highly doubtful:However, organic layers having aromatic moieties and reactive chemical groups, as adenine and mellitic acid, lead to the formation of photoresistant solid residues, probably of macromolecular nature, which could exhibit a longer photostability. Such solid organic layers are found in micrometeorites or could have been formed endogenously on Mars. Finally, the quantum efficiencies of photodecomposition at wavelengths from 200 to 250 nm, determined for each of the studied molecules, range from 10−2 to 10−6 molecule photon−1 and apply for isolated molecules exposed at the surface of Mars. These kinetic parameters provide essential inputs for numerical modeling of the evolution of Mars’ current reservoir of organic molecules. Organic molecules adsorbed on martian minerals may have different kinetic parameters and lead to different endproducts. The present study paves the way for the interpretation of more complex simulation experiments where organics will be mixed with martian mineral analogs.The results are pretty depressing. They could only imagine organics lasting longer if they formed solid gunk, or if they were mixed in with Martian soil. Either way, such delicate molecules would hardly be available for life in water, where the reactions would have to take place. Put them on the surface exposed to UV, though, and 100 photons might be enough to destroy them (a million photons for the hardiest). It wouldn’t take very long for that many photons to sunburn the naked molecules to death.Hope Against HopeDepressing results like these do little to dampen the enthusiasm of materialists who hope against hope that life can emerge from unguided natural processes without design. For instance, Space.com reported that SETI researchers might be able to find aliens from their stinking pollution. The “primordial soup” phrase made it into Ian Wright’s headline on The Conversation about Rosetta and the comet. And despite previous discouragements about the habitable zones of red dwarfs, Astrobiology Magazine titillated the imagination of its readers with the dream that planets orbiting red dwarfs just might, actually, be the best places to discover alien life.The dream is a lie (to mangle a phrase). So are the building blocks of lie (3/19/08) and the primordial goop (5/21/01). Get real, we challenge the astrobiologists: you need energy to jumpstart life, so be our guest: put your building blocks out there in the sun (5/28/03). After all, don’t you argue that since the Earth is an open system, open to the energy of the sun, that’s why evolution doesn’t violate thermodynamics? Don’t some origin-of-life experts promote UV radiation as a viable energy source to create the building blocks? Better hope life emerges quick before the little organic potatoes in the soup turn into fringe fries.For some needed deprogramming from the cult of astrobiology, read this illustrated thought experiment by Granville Sewell, a thermodynamicist, on Evolution News & Views.