MIT researchers have discovered that amino acids — main constructing blocks for all times on Earth — are steady in extremely concentrated sulfuric acid. Their outcomes assist the concept that these identical molecules could also be steady in Venus’ extremely sulfuric clouds. Credit score: JAXA/J. J. PetkowskiResults counsel the clouds of Venus could possibly be hospitable for some types of life.If there may be life within the photo voltaic system past Earth, it may be discovered within the clouds of Venus. In distinction to the planet’s blisteringly inhospitable floor, Venus’ cloud layer, which extends from 30 to 40 miles above the floor, hosts milder temperatures that might assist some excessive types of life.If it’s on the market, scientists have assumed that any Venusian cloud inhabitant would look very totally different from life kinds on Earth. That’s as a result of the clouds themselves are made out of extremely poisonous droplets of sulfuric acid — an intensely corrosive chemical that’s recognized to dissolve metals and destroy most organic molecules on Earth.However a brand new examine by MIT researchers could problem that assumption. Revealed on March 18 within the journal Astrobiology, the examine experiences that, in reality, some key constructing blocks of life can persist in options of concentrated sulfuric acid.The examine’s authors have discovered that 19 amino acids which are important to life on Earth are steady for as much as 4 weeks when positioned in vials of sulfuric acid at concentrations just like these in Venus’ clouds. Particularly, they discovered that the molecular “spine” of all 19 amino acids remained intact in sulfuric acid options ranging in focus from 81 to 98 p.c.“What is completely stunning is that concentrated sulfuric acid isn’t a solvent that’s universally hostile to natural chemistry,” says examine co-author Janusz Petkowski, a analysis affiliate in MIT’s Division of Earth, Atmospheric and Planetary Sciences (EAPS).“We’re discovering that constructing blocks of life on Earth are steady in sulfuric acid, and that is very intriguing for the thought of the potential for life on Venus,” provides examine creator Sara Seager, MIT’s Class of 1941 Professor of Planetary Sciences in EAPS and a professor within the departments of Physics and of Aeronautics and Astronautics. “It doesn’t imply that life there would be the identical as right here. The truth is, we all know it could actually’t be. However this work advances the notion that Venus’ clouds may assist advanced chemical compounds wanted for all times.”The examine’s co-authors embrace first creator Maxwell Seager, an undergraduate within the Division of Chemistry at Worcester Polytechnic Institute and Seager’s son, and William Bains, a analysis affiliate at MIT and a scientist at Cardiff College.Constructing Blocks in AcidThe seek for life in Venus’ clouds has gained momentum lately, spurred partially by a controversial detection of phosphine — a molecule that’s thought of to be one signature of life — within the planet’s environment. Whereas that detection stays underneath debate, the information has reinvigorated an outdated query: Might Earth’s sister planet really host life?Searching for a solution, scientists are planning a number of missions to Venus, together with the primary largely privately funded mission to the planet, backed by California-based launch firm Rocket Lab. That mission, on which Seager is the science principal investigator, goals to ship a spacecraft by means of the planet’s clouds to research their chemistry for indicators of natural molecules.Forward of the mission’s January 2025 launch, Seager and her colleagues have been testing varied molecules in concentrated sulfuric acid to see what fragments of life on Earth may additionally be steady in Venus’ clouds, that are estimated to be orders of magnitude extra acidic than probably the most acidic locations on Earth.“Individuals have this notion that concentrated sulfuric acid is an especially aggressive solvent that may chop the whole lot to items,” Petkowski says. “However we’re discovering this isn’t essentially true.”The truth is, the crew has beforehand proven that advanced natural molecules resembling some fatty acids and nucleic acids stay surprisingly steady in sulfuric acid. The scientists are cautious to emphasise, as they do of their present paper, that “advanced natural chemistry is in fact not life, however there isn’t a life with out it.”In different phrases, if sure molecules can persist in sulfuric acid, then maybe the extremely acidic clouds of Venus are liveable, if not essentially inhabited.Of their new examine, the crew turned their concentrate on amino acids — molecules that mix to make important proteins, every with their very own particular operate. Each residing factor on Earth requires amino acids to make proteins that in flip perform life-sustaining capabilities, from breaking down meals to producing power, constructing muscle, and repairing tissue.“Should you think about the 4 main constructing blocks of life as nucleic acid bases, amino acids, fatty acids, and carbohydrates, we have now demonstrated that some fatty acids can kind micelles and vesicles in sulfuric acid, and the nucleic acid bases are steady in sulfuric acid. Carbohydrates have been proven to be extremely reactive in sulfuric acid,” MaxwellSeager explains. “That solely left us with amino acids because the final main constructing block tostudy.”A Secure BackboneThe scientists started their research of sulfuric acid through the pandemic, finishing up their experiments in a house laboratory. Since that point, Seager and her son continued work on chemistry in concentrated sulfuric acid. In early 2023, they ordered powder samples of 20 “biogenic” amino acids — these amino acids which are important to all life on Earth. They dissolved every kind of amino acid in vials of sulfuric acid blended with water, at concentrations of 81 and 98 p.c, which symbolize the vary that exists in Venus’ clouds.The crew then let the vials incubate for a day earlier than transporting them to MIT’s Division of Chemistry Instrumentation Facility (DCIF), a shared, 24/7 laboratory that provides plenty of automated and handbook devices for MIT scientists to make use of. For his or her half, Seager and her crew used the lab’s nuclear magnetic resonance (NMR) spectrometer to research the construction of amino acids in sulfuric acid.After analyzing every vial a number of occasions over 4 weeks, the scientists discovered, to their shock, that the fundamental molecular construction, or “spine” in 19 of the 20 amino acids remained steady and unchanged, even in extremely acidic circumstances.“Simply displaying that this spine is steady in sulfuric acid doesn’t imply there may be life on Venus,” notes Maxwell Seager. “But when we had proven that this spine was compromised, then there can be no probability of life as we all know it.”“Now, with the invention that many amino acids and nucleic acids are steady in 98 p.c sulfuric acid, the potential for life surviving in sulfuric acid is probably not so far-fetched or implausible,” says Sanjay Limaye, a planetary scientist on the College of Wisconsin who has studied Venus for over 45 years, and who was not concerned with this examine. “In fact, many obstacles lie forward, however life that developed in water and tailored to sulfuric acid is probably not simply dismissed.”The crew acknowledges that Venus’ cloud chemistry is probably going messier than the examine’s “check tube” circumstances. For example, scientists have measured varied hint gases, along with sulfuric acid, within the planet’s clouds. As such, the crew plans to include sure hint gases in future experiments.“There are just a few teams on this planet now which are engaged on chemistry in sulfuric acid, and they’ll all agree that nobody has instinct,” provides Sara Seager. “I feel we’re simply extra completely happy than something that this newest outcome provides yet one more ‘sure’ for the potential for life on Venus.”Reference: “Stability of 20 Biogenic Amino Acids in Concentrated Sulfuric Acid: Implications for the Habitability of Venus’ Clouds” by Maxwell D. Seager, Sara Seager, William Bains, and Janusz J. Petkowski, 18 March 2024, Astrobiology.DOI: 10.1089/ast.2023.0082