Revisiting the Need for Water to Live
Scientists have taken for granted that water is the essential ingredient for life for decades now, which has influenced how we look for planets where we can live. But a recent Massachusetts Institute of Technology (MIT) study asks us to rethink this age-old assumption by proposing that extraterrestrial life might be sustainable in completely different liquids.
Laboratory tests suggest that some salts, which exist as liquid at a broad range of temperatures and pressures, could be another home of life. These liquids are called ionic liquids and are stable below 100 degrees Celsius, the temperature at which a normal liquid would boil. These liquids could also host the vital life-signature molecules such as proteins.
“If we expand our definition of life-supporting fluids to include anything other than water, then the potential for rocky planets to be habitable increases hugely,” co-author Rachana Agrawal wrote. “Ionic liquids might make life possible even on planets that are too hot or have atmospheres that are too thin to support liquid water.”
Ionic liquids are predominantly man-made on our planet, with a single exception: a liquid salt that forms when two species of ant venoms combine. The researchers at MIT looked into how such liquids would normally form in nature, investigating the reaction between sulfuric acid and 30 nitrogenous organic compounds under different temperatures and pressures.
To simulate planetary surfaces, the researchers even tested the mixtures on basalt rock, prevalent on most rocky planets. Incredibly, ionic liquids created under remarkably broad sets of conditions, including temperatures as high as 180 degrees Celsius and very low pressures far below Earth’s atmospheric pressures.
Sara Seager, co-lead author, explained, “No matter what mixture we used, ionic liquids still occurred. Even when sulfuric acid infiltrated rock pores, there remained stable drops of ionic liquid on the surface.”
It suggests that worlds without liquid water may still have small reservoirs of ionic liquid where organic chemicals concentrate, thus having habitable niches for extraterrestrial biochemistry.
Implications for Alien Life and Future Research
The research indicates that rocky planets hotter than Earth and without water may be able to support life if they possess sulfuric acid as a result of volcanic eruptions and caches of organic molecules both of which are widespread throughout the solar system.
“This opens up Pandora’s box of possibilities,” said Dr. Seager. “We now have an entirely new field of research into how life could possibly be in environments radically different from Earth.”
Scientists anticipate investigating which life-signature molecules may survive and operate within these foreign fluids and, perhaps, broaden the horizon of astrobiology and the quest for extraterrestrial life.
With this finding, the scientific community might have to reconsider criteria for habitability, turning their attention away from water-centered worlds to worlds in which exotic liquid salts may harbor alien life.
ALSO READ: Alien: Earth Stars Essie Davis & Erana James Recall Bonding with Adarsh Gourav Over Lagaan
