You may not know it but you're left-handed. We're not talking about the hand you use the most but rather the amino acids in the molecules in your body. All life in earth uses "left-handed" molecules as building blocks. And a research team led by associate Western Michigan University physics professor Michael Famiano is trying to find out why that's true, and whether the "stuff of life" was forged in the depths of space.
Famiano says amino acids come in both left- and right-handed forms. But living organisms only use the left-handed kind, and Famiano says scientists have long wanted to know why. He says research by his team suggests that there could be an out-of- this-world explanation - literally. That's because organic molecules found on meteorites that have fallen to earth are also overwhelmingly left-handed. Famiano says that suggests the possibility that organic compounds created elsewhere in the universe may have jump-started the process that created life on this planet. He's quick to point out that there are other scenarios, though.
Famiano says his team's work suggests that organic molecules in space like amino acids may be mostly left-handed because of bombardment by sub-atomic particles called leptons. They also exhibit "handed" properties for reasons that are not understood yet. But Famiano says the leptons may interact with amino acids in ways that destroy the right-handed variety, leaving only those that are lefties. He says experiments are needed to test that theory, something that could be difficult.
The theory, if it is confirmed, raises questions about the nature of any extraterrestrial lifeforms. Famiano says he wonders if there might be life in other star systems, including intelligent life, that's based on right-handed amino acids, and what that life might be like.