How do we know organic molecules abound in stellar objects such as the Eagle Nebula? The science of radio astronomy is essential in understanding the inner workings of these vast clouds.
Each type of organic molecule absorbs a particular wavelength in the electromagnetic spectrum. Radio telescopes on Earth measure the EM waves coming from distant stars located on the far side of the nebula.
As the distant starlight passes through the clouds, astronomers know that certain diagnostic wavelengths will be weaker in the background, others stronger in the foreground.
At the NASA Ames Research Center, astrochemist Dr. Louis Allamandola created experimental conditions akin to those inside the Eagle Nebula.
First, Allamandola chilled a vacuum chamber to very low temperatures.
Next, he introduced a spray of gases found in molecular clouds - diatomic and triatomic chemical species such as hydrogen, carbon dioxide, carbon monoxide and water. Finally, he passed a beam of UV radiation into the chamber and examined the spectrum of the chemicals produced by the reaction with UV radiation.
The resulting reactions produced large molecules such as nitriles (carbon and nitrogen) and ethers (hydrocarbons linked to oxygen as well as alcohol. Some amino acids were detected, too, compounds very similar to the building blocks of living cellular membranes.
What's in the Sky: Want to search for M16, the Eagle Nebula? You'll need a reliable telescope and a dark sky. According to European astronomers Hartmut Frommert and Christine Kronberg, "M16 is found rather easily either by locating the star Gamma Scuti, a white giant star of magnitude 4.70. Or from Altair (Alpha Aquilae) via Delta and Lambda Aql.; M16 is about 2.5 degrees (19 min. in R.A.) west of this star. M16 and the Eagle Nebula are best seen with low powers in telescopes."
Lou Varricchio, M.Sc., was a science writer at the NASA Ames Research Center in Mountain View, Calif. He is currently a member of the NASA-JPL Solar System Ambassador program in Vermont. In 2009, he earned the U.S. Civil Air Patrol's Gen. Charles E. 'Chuck' Yeager Aerospace Education Achievement Award.