Complex organic molecules, the building blocks of life, have been detected in a young star system for the first time. The finding confirms that the conditions that spawned life on Earth appear to be more than a one-time event. Astronomers made the discovery using the Atacama Large Millimeter/submillimeter Array (ALMA) and published their results last week in the journal Nature.
From studying comets (artefacts from the formation of the Solar System), scientists were able to predict that the protoplanetary disc of the young star might be filled with water and organic molecules. The observations made with the ALMA telescope uncovered that the protoplanetary disc surrounding the million-year-old infant star, MWC 480, contained enough amounts of methyl cyanide (CH3CN) and hydrogen cyanide (HCN) to fill Earth’s oceans. The molecules were found in a region similar to the Solar System’s Kuiper belt (the region past Pluto where icy comets and cold planetesimals are found). Methyl cyanide is a complex carbon-based molecule that contains nitrogen bonds, which assist in the production of amino acids – structural elements of the proteins essential for life.
“From the study of exoplanets, we know the Solar System is [fairly regular] in its number of planets [and] abundance of water,” says lead author of the new paper Karin Öberg, an astronomer at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, USA. “We now have evidence that this same chemistry exists elsewhere in the Universe, in regions that [might] form solar systems [like] our own.”
The ALMA is a combination of radio telescopes located in the Atacama Desert of northern Chile. The dry sand and high altitude are crucial to millimetre wavelength measurements. ALMA was constructed with the aim of gaining an insight into star birth during the early universe as well as providing detailed images of local star and planet formation. On 11th August 2014, astronomers published studies after using the ALMA for the first time, showing a thorough distribution of hydrogen cyanide among other molecules inside comets. Now, the technology has observed complex organic molecules surrounding an MWC 480.
The star MWC 480 is double the mass of the Sun and shines nearly ten times brighter. It is 455 light-years away in the Taurus star-forming region. The disc surrounding the young star is thought to be in the initial stages of growth having recently combined from a cold, dark nebula of dust and gas. While astronomers have observed simple discs surrounding other young stars, complex organic molecules, such as methyl cyanide, have only just been discovered.
Until now, astronomers have only observed these organic molecules in the cold and distant depths of interstellar space clouds and it was uncertain if they might survive the powerful radiation emitted by young stars. Now the question is: what chance do these molecules have of surviving as the young star matures into an established exo-system? Since a much larger amount was observed in the disc compared to interstellar clouds, researchers believe that these complex organic molecules are being produced efficiently and quickly – these two properties are essential to its survival. The rapid formation of molecules is reportedly necessary to outrun the forces that might otherwise pull the molecules apart. Therefore, other objects may capture these molecules as they disperse throughout the evolving exo-system, potentially seeding life similarly to Earth’s own Solar System.
Earth’s prebiotic organic chemistry might be more typical than once thought. Furthermore, the research demonstrates how humans might be far from unique as well. Öberg concluded that, “From a life in the Universe point of view, this is great news.”
What other signs from beyond Earth’s atmosphere might point to life elsewhere in the universe?