Does non-water-based life exist?

Chuck Bednar for redOrbit.com – @BednarChuck

Much of the search for extraterrestrial life on Mars and in other parts of the universe has thus far centered around the hunt for water – mostly because all life as we know it needs water to live. But what if we’re ignoring other types of life?

That fascinating possibility is examined by the authors of a study published in a recent edition of the journal Astrobiology, who according to Space.com examine whether a liquid other than good old-fashioned H2O could support life in a place such as Saturn’s icy moon Titan.

Titan, they explained, is rich in the hydrocarbon methane, which would keep water-based RNA and DNA molecules from carrying a genetic blueprint. Other molecules would have to step up and fill this role. The study proposes ethers, a type of molecule not used in any Earth-based genetics, could support alien life.

However, Steven Benner, lead author of the study and a distinguished fellow at the Foundation for Applied Molecular Evolution, explained that Titan would be too cold for this to happen. It would require a far-warmer, methane-rich world to support the genetic molecules Benner and his colleagues are proposing – a type of exoplanet that they refer to as “warm Titans.”

Warm Titans could potentially support ether-based life

Thus far, no “warm Titans” close enough to their stars have been found during the hunt for exoplanets. However, he claimed that his team is hopeful that there are several such worlds waiting to be discovered.

In their study, the authors wrote, “Ethers are proposed here as the repeating backbone linking units in linear genetic biopolymers that might support Darwinian evolution in hydrocarbon oceans. Hydrocarbon oceans are found in our own solar system as methane mixtures on Titan,” and they may be found as mixtures of higher alkanes such as propane.

They studied several types of polyethers in propane over a range of different temperatures. They found that these compounds are “reasonably soluble” at temperatures around 200 K, but this solubility decreases dramatically at temperatures below 170 K, which is still well over the 95 K of Titan’s methane oceans, the authors explained.

It’s possible, we just haven’t found it yet

“Assuming that a liquid phase is essential for any living system, and genetic biopolymers must dissolve in that biosolvent to support Darwinism, these data suggest that we must look elsewhere to identify linear biopolymers that might support genetics in Titan’s surface oceans,” they noted.

On warm Titans, “where abundant organics and environments lacking corrosive water might make it easier for life to originate,” however, ether-based genetic molecules “may be suitable to support life in hydrocarbon oceans.”

So hypothetically, yes, non-water based life can exist. This life doesn’t seem to be in our galactic neighborhood, but scientists are hopeful for finding the right conditions in the future.

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Source: http://www.redorbit.com/news/space/1113396433/does-non-water-based-life-exist-052315/