Handedness Could Reveal Aliens
Researchers at the National Institute of Standards and Technology are developing a way to measure the directionality of compounds on other planets--which could reveal the presence of life, because biomolecules tend to twist in only one of two possible directions. Karen Hopkin reports
SUBSCRIBE TO Science Quickly
On supporting science journalism
If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
[The following is an exact transcript of this podcast.]
Many of the key molecules for life have a specific direction, or handedness: DNA twists to the right, amino acids to the left. Now scientists at the National Institute of Standards and Technology (or NIST) aim to take advantage of this so-called chirality to search for signs of extraterrestrial life.
When chemists synthesize organic compounds in the lab, they often wind up with a mix of molecules: half are right-handed, and half are left. But cells are a bit more particular. When life arose, our ancestors made some choices. They went with the right-handed sugars, and the left-handed amino acids, a tradition still in effect.
The scientists at NIST have come up with a gadget that can see the polarized light that bounces off of molecules that show a preferred handedness. And in the Proceedings of the National Academy of Sciences, they report using the device to detect the signature reflection that comes from the chlorophyll in plant leaves. If this handedness meter works well at a distance, they could load it onto a space probe—a preponderance of right- or left-handed biomolecules could mean a planet has at least simple life forms on it. And we might even find out if ET is a southpaw.
—Karen Hopkin
It’s Time to Stand Up for Science
If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.
I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.
If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.
In return, you get essential news, captivating podcasts, brilliant infographics, can't-miss newsletters, must-watch videos, challenging games, and the science world's best writing and reporting. You can even gift someone a subscription.
There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.
