The research team at NASA's Jet Propulsion Laboratory in Pasadena, California is the first direct look at the organic reactions that take place on icy particles in the frigid reaches of our solar system, and in the even chillier places between stars.
Scientists think that the basic ingredients of life, including water and organics, began their journey to Earth on these lonesome ice particles, a NASA statement said.
The ice and organics would have found their way into comets and asteroids, which then fell to Earth, delivering "prebiotic" ingredients that could have jump-started life.
The various steps needed to go from icy organics to slime molds are not clear, but the new findings help explain how the process works.
"The very basic steps needed for the evolution of life may have started in the coldest regions of our universe. We were surprised to see organic chemistry brewing up on ice, at these very cold temperatures in our lab," said Murthy Gudipati, lead author of the new study at JPL.
The organics are called polycyclic aromatic hydrocarbons, or PAHs. These carbon-rich molecules can be found on Earth as combustion products.
Gudipati and colleague Rui Yang of JPL used their lab set-up to mimic the environment of icy PAH molecules in the quiet cold of space, at temperatures as low as minus 268 degrees Celsius.
The results revealed that the PAHs had transformed and incorporated hydrogen atoms into their structure and lost their circular, aromatic bonds.
This is the type of change that would need to occur if the material were to eventually become amino acids and nucleotides-bits and pieces of protein and DNA, respectively.
"PAHs are strong, stubborn molecules, so we were surprised to see them undergoing these chemical changes at such freezing-cold temperatures," said Gudipati.
The research is that it might explain the mystery of why PAHs have not yet been identified on ice grains in space.
The new findings show that PAHs, once they stick to the ice surface, are chemically transformed into other complex organics, explaining why they might not be seen.
Their work was published in the Astrophysical Journal Letters.
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