The newly detected presence of two complex organic molecules in the Milky Way suggests the building blocks for life may exist in space even before the formation of planets.
Located close the center of the galaxy, the molecular cloud Sagittarius B2 is something akin to a galactic watering hole. A popular hangout for biologists and chemists looking for the building blocks of life in space, it contains a rich stew of materials in the process of being recycled into stars and planets.
Within the cloud are a wide variety of organics, now known to include two of the most complex molecules ever found in interstellar space — ethyl formate and n-propyl cyanide. The molecules are similar in size and complexity to amino acids, the building blocks of life.
"It shows that you can go to this high level of complexity in space. These are comparable to the simplest amino acids," said Cornell astrochemist Robin Garrod, who presented the findings along with colleagues from Germany's Max Planck Institute for Radio Astronomy and the University of Cologne at this week's European Astronomy and Space Science conference in the United Kingdom.
"What's interesting is how they formed and that we even found them," Garrod told Discovery News.
Scientists made the discovery by disentangling the molecules' chemical fingerprints within radio waves also carrying the signatures of hundreds of smaller molecules. Within 3,700 such signatures from a region of Sagittarius B2 known as the Large Molecule Heimat, the researchers identified 36 that belonged to the two newly identified molecules.
"In the lab, we only look at one type of molecule at a time. But when we look in space, all the molecules are there at the same time. That's the difficulty," said Eric Herbst, a theoretical and chemical physicist at Ohio State University.
Computer simulations indicate that the molecules did not assemble themselves atom-by-atom, but came together in sections using already formed blocks that were available on grains of dust.
"It's the only formation method that is remotely able to reproduce the abundances and ratios that we see between the different sizes of molecules," Garrod told Discovery News.
"It certainly raises the possibility that you have many of the building blocks for life in space before even a planet is formed, which increases the chances for life to form, at least in my view," he added.
The observations were made with Spain's IRAM radio telescope. The research is being published in an upcoming issue of Astronomy & Astrophysics.