Organic Concoctions On Ice May Reveal How Life Started On Earth

Icy organics may not be your idea of coffee to die for, but over in Pasadena, California, NASA's researchers are busy making icy organic concoctions, or carbon-bearing molecules. These molecules are then zapped with lasers. The goal is noble: to find out how life began on our planet.

According to the latest edition of Astrophysical Journal Letters, those researchers drew their inspiration when gazing out into the vastness of our solar system. They must have wondered about the origin and the chemical makeup of those icy particles which float freely in the chilly environment among the stars. It is a popular belief that life originates from organics and water, but not many folks know that these lonesome icy particles are probably responsible to start life on Earth. Scientists believe that the combination of organics and ice particles would very likely to have bumped into asteroids and comets, which subsequently crash-landed on Earth, thus providing the necessary "prebiotic" ingredients to jump start life here.

It may be difficult to visualize the transition from icy organics into slimy molds but the experiments conducted at NASA's lab definitely demonstrated that the process to turn an organic material into prebiotic ingredients can taken place while the organics are deep inside icy structure.

"The very basic steps needed for the evolution of life may have started in the coldest regions of our universe," according to lead researcher of the new study at Jet Propulsion Laboratory, NASA (or simply JPL), Murthy Gudipati. Indeed the researchers were stumped as the organic chemistry was re-enacted inside the extremely cold temperature settings inside the lab.

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The organics in question here are PAHs (acronym for polycyclic aromatic hydrocarbons). They are filled with carbon-rich molecules and also common sights on Earth; like candle soot and even carbon vapor coming out of the exhaust pipe of motor-vehicle. They exist in abundance in outer space in asteroids, comets, and even distant objects, e.g. the void space separating the stars and in far-far away galaxies, as confirmed by NASA's Spitzer Space Telescope.

Murthy and his JPL colleagues have successfully mimicked the icy PAH molecules in outer-space with laboratory settings. With temperature sets to a low of 5 Kelvin (i.e. -450 degrees Fahrenheit, or -268 Celsius), UV rays are beamed onto the particles, to simulate the bombardment from stars. It was then followed by a special laser system called Matrix Assisted Laser Desorption and Ionization (a.k.a. MALDI) to reproduce the same chemical reaction. MALDI is meant to zap the ice with both UV lasers and infrared rays.

Under such lab settings, PAHs did transform: additional hydrogen atoms were absorbed and a new yet complex structure emerged. The resultant organics have lost their circular shape and aromatic bonds. Past scientific experiments have proven that this is the sort of change that a material would need to go through before it eventually turn into nucleotides and amino acids – fragments of DNA and protein, respectively.

It was a surprised finding. PAHs are known to be strong and resilient, so the chain of chemical reactions under super cold temperatures was unfathomable in the past.

An expected bonus for this experiment is that scientists may have found their answer about why the absence of PAHs on ice grains. Given that this strong and resilient organic is almost omni-present in the universes, hot dusts and gases, it was indeed puzzling there is no trace of PAH on ice. The fact that PAHs could quickly turn into more complex structures as they got stuck to the ice should help explain their absence on ice surface.

While this finding points us to those very cold regions of the universe as we continue our pursuit of life origin, one fundamental question to follow would be: Where the icy particles come from, way beyond our sun? Nobody knows for now, but this finding is surely a huge step in our efforts to unlock the mystery of life on Earth.