Rensselaer astronomers study the stuff of future planets in an interstellar cloud

New stars and planetary systems are born within the cold, dark regions of interstellar clouds. To help us better understand the origins of our own solar system, and the myriad of others now known to exist, astronomers study these clouds at the evolutionary phase immediately preceding stellar birth. A good example is the object known as Lynds 183, a small, compact dark cloud known from observations made at radio wavelengths to be rich in gaseous interstellar molecules such as carbon monoxide, ammonia, methanol and hydrogen cyanide, all existing at temperatures as low as 10 degrees Kelvin. A new study published in the September 10, 2013 issue of the Astrophysical Journal helps to expand our picture of the cloud by focusing on the solids – silicate dust and ices – that are potential raw materials for future planets. A team led by Doug Whittet and Charles Poteet at RPI used infrared data obtained from NASA’s Spitzer Space Telescope and the Mauna Kea Observatory in Hawaii to search for the spectroscopic fingerprints of these material. They found that the silicate particles serve as nucleation centers for the growth of ices that contain not only H2O but also CO and CO2 (dry ice), and that this can occur in the outer layers of the cloud where there is just enough shielding from the harsh environment of space to allow the ices to survive. These results add to the growing evidence that the water and other volatiles needed to form habitable environments on earth-like planets are easily formed at the lowest temperatures in prestellar clouds. When stars are born inside them, the resulting  increase in temperature and radiation exposure can drive a different kind of chemistry that can form complex organic molecules out of these simple ices.

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