All Life on Earth can not live without water, so when scientists are looking for alien life, they always ask first: “Is there water there?”
But the“Law of water” may not be the only answer. Scientists at the Massachusetts Institute of Technology (MIT) in the US recently made the unexpected discovery that the habitability of some planets may have nothing to do with water. A special fluid, called an ionic liquid, may well have been formed from chemicals that are common on the surfaces of certain rocky planets and moons.
Ionic liquids are actually special liquid salts that do not evaporate as easily as water and can persist in hotter, drier, and“Harsher” places.
At the time, MIT scientists were investigating the possibility of life in the clouds of Venus. Venus’ clouds are filled with highly toxic sulfuric acid, which must first be vaporized to see if there are any signs of life left over from organic matter. So they mixed sulfuric acid with glycine in the lab to see what remained after evaporation. Results after each experiment, although most of the liquid sulfuric acid will evaporate, but there will always be a layer of stubborn liquid film. They soon realized that this was the ionic liquid formed by the chemical reaction between sulfuric acid and glycine.
The unexpected discovery led to a revolutionary conjecture: could ionic liquids form naturally on planets that are too hot and have thin atmospheres for water to exist?
To test the idea, they mixed more than 30 nitrogen-containing organic compounds with sulfuric acid, at different temperatures and pressures, and dropped them on common rocks like basalt. Experiments have shown that ionic liquids can form and remain liquid for long periods of time, no matter how the conditions change. Even more surprising, the liquid can survive at temperatures as high as 180 ° C, well below Earth’s atmospheric pressure. This means that ionic liquids can occur naturally, even on planets that have no water at all, if conditions are right.
More importantly, this fluid can be an ideal carrier for certain biomolecules, such as certain proteins in which to maintain structural stability. This suggests that life may not have to depend on water, but that it is possible to live with metabolic fluids.
Excited by the discovery, the scientists next plan to test which molecules of life can survive and even reproduce in ionic liquids to see if it can really be a breeding ground for alien life.
The research broadens the understanding of earth-like Planetary habitability and provides new insights into the search for extraterrestrial life. Perhaps in the future, the search for extraterrestrial life will be aimed at those strange liquid world, and bring unexpected discoveries.