Credit: NASA/JPL-Caltech/F. Lahuis (Leiden Observatory)

Life's Starting Materials Found in Dusty Disk

This graph, or spectrum, from NASA's Spitzer Space Telescope tells astronomers that some of the most basic ingredients of DNA and protein are concentrated in a dusty planet-forming disk circling a young sun-like star called IRS 46. These data also indicate that the ingredients -- molecular gases called acetylene and hydrogen cyanide -- are located in the star's terrestrial planet zone, the region where scientists believe Earth-like planets would be most likely to form.

The data were acquired by Spitzer's infrared spectrograph, which splits light from the star's disk into distinct features characteristic of a particular chemical. The features, seen here as bumps and squiggles, are like bar codes used in supermarkets to identify different products. In this case, the products are the two DNA and protein precursors, acetylene and hydrogen cyanide, as well as carbon dioxide gas. All three gases are termed "organic" because they contain the element carbon.

The shapes of the features in this spectrum helped pinpoint the location of the gases in the star's disk. A feature's shape reflects the temperature of the gas. By comparison with model spectra, astronomers were able to deduce that the gases are present in regions where the temperature ranges from approximately the boiling point of water on Earth (212 degrees Fahrenheit), to nearly a thousand degrees Fahrenheit. Such hot temperatures place the gases in the star's terrestrial planet zone, which is sometimes referred to as the "Goldilocks" zone because it is just right for Earths.

Acetylene and hydrogen cyanide are some of life's most basic starting materials. If you mix them together in a test tube with water, and give them some kind of surface on which to be concentrated and react, you'll get a slew of organic compounds, including many of the 20 essential amino acids and one of the four chemical units, called bases, that make up DNA.

About the Object	Object Name: IRS 46 (also known as YLW16b, GY274) Object Type: young stellar object Position (J2000): RA: 16h 27m 29.4s Dec: -24d 39m 16.3s Distance: 125 pc (410 light-years) Constellation: Ophiuchus
About the Data	Image Credit: NASA/JPL-Caltech/F. Lahuis (Leiden Observatory) Instrument: IRS SH / LH Wavelength: 9.9 - 19.6 microns / 18.7-37.2 microns Exposure Date: 2004 August 29 Exposure Time: 125.8s / 58.7s Release Date: Dec. 20, 2005
Observers	Fred Lahuis (Leiden Observatory) Neal Evans (University of Texas at Austin) Ewine F. van Dishoeck (Leiden Observatory) A. C. Adwin Boogert (California Institute of Technology) Klaus Pontoppidan (Leiden Observatory) Geoffery Blake (California Institute of Technology) Cornelius Dullemond (Max-Plank-Institut fur Astronomie) Michiel Hogerheijde (Leiden Observatory) Jes Jorgensen (Harvard-Smithsonian Center for Astrophysics) Jacqueline Kessler-Silacci (University of Texas at Austin) Claudia Knez (University of Texas at Austin)

The Spitzer Space Telescope is a NASA mission managed by the Jet Propulsion Laboratory. This website is maintained by the Spitzer Science Center, located on the campus of the California Institute of Technology and part of NASA's Infrared Processing and Analysis Center.