科学美国人60秒:Star-Forming Clouds May Spit Out Life’s Building Blocks

The ingredients for life on Earth may have gotten a start in space. Many biologically important molecules have been seen in space or found in meteorites. Now astronomers have discovered one of the largest and most complex organic molecules yet in a gaseous star-forming region of interstellar space. 

Most organic molecules seen in interstellar space, thanks to their spectra, are just straight chains of carbon atoms. The newfound molecule, isopropyl cyanide, on the other hand, has branching carbon chains. Such branches are needed for many molecules crucial to life, such as the amino acids that build proteins.

Researchers found the isopropyl cyanide’s chemical imprints in light from the Sagittarius B2 cloud about 27,000 light-years away. To reach the sensitivity needed to spot the faraway molecule, the scientists used the connected web of 66 radio telescopes that make up the Atacama Large Millimeter/submillimeter Array, also known as ALMA, in Chile. They report their findings in the journal Science. [Arnaud Belloche et al: Detection of a branched alkyl molecule in the interstellar medium: iso-propyl cyanide]

The discovery supports the idea that life’s building blocks may have originated in interstellar space. The molecules could have arisen during the process of early star formation, and been transferred to our planet later. Of course, that still doesn’t explain the origin of life—or why it ultimately came up with that wacky cousin you have to see at Thanksgiving.

—Clara Moskowitz