Many scientists think that life on Earth began when, at a time when it was ready to support life, comets and asteroids carrying water and complex organic molecules crashed into the planet and planted the seeds.
These objects likely would have come from the outer solar system. The region of our solar system beyond Neptune contains the Kuiper Belt and the Oort cloud. It is a region of cold planetesimals, asteroids, comets, dust and other leftovers from the formation of our solar system.
Using observations from the the European Southern Observatory (ESO) Atacama Large Millimeter/submillimeter Array (ALMA) telescope high in the Chilean Andes, researchers have found a protoplanetary disc containing complex carbon-based molecules.
The observations of a region roughly analogous to the Kuiper Belt around the star MWC 480[1] show that it contains enough methyl cyanide (CH3CN) to “fill all of Earth’s oceans” as well as large amounts of hydrogen cyanide (HCN).
“Studies of comets and asteroids show that the solar nebula that spawned the Sun and planets was rich in water and complex organic compounds. We now have even better evidence that this same chemistry exists elsewhere in the Universe, in regions that could form solar systems not unlike our own,” said Karin Öberg in a statement.
Öberg is an astronomer with the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts and lead author of the paper “The Cometary Composition of a Protoplanetary Disk as Revealed by Complex Cyanides” appearing in the journal Nature on April 9.
MWC 480 is roughly twice the size of our Sun and located 455 light-years from Earth in the Taurus star-forming region. The star is relatively newly formed and its solar system appears to be in the very early stages of forming. Although current telescopes may not be powerful enough to detect small objects, no planetary bodies have been detected to date.
In other words, if a solar system similar to ours is forming around MWC 480 it will be a few billion years before advanced life forms appear.
Interstellar clouds have long been thought to be factories for complex organic molecules, including cyanides. According to the researchers methyl cyanide is particularly important because it contains carbon-nitrogen bonds which are essential to the formation of amino acids. Amino acids, in turn, are essential to the formation of proteins, the building blocks of life.
It was not known, however, if these complex organic molecules could form and survive in the unstable environment of a young solar system. The AMLA observations show that the molecules do better than survive. The protoplanetary disc actually seems to be an efficient incubator of such molecules.
The presence cyanide molecules were more abundant than would be expected in the interstellar, star forming, cloud. The researchers expect that as the solar system continues to evolve, the carbon molecules will be delivered to new planets and potentially environments where life could evolve.
“From the study of exoplanets, we know the Solar System isn’t unique in its number of planets or abundance of water. Now we know we’re not unique in organic chemistry. Once more, we have learnt that we’re not special. From a life in the Universe point of view, this is great news,” said Öberg.
