* Astronomy

Blobrana · L

RE: Diffuse interstellar bands

Blobrana · L

In Distant Galaxies, New Clues to Century-Old Molecule Mystery

In a study that pushes the limits of observations currently possible from Earth, a team of NASA and European scientists recorded the "fingerprints" of mystery molecules in two distant galaxies, Andromeda and the Triangulum. Astronomers can count on one hand the number of galaxies examined so far for such fingerprints, which are thought to belong to large organic molecules, says the team's leader, Martin Cordiner of the Goddard Center for Astrobiology at NASA's Goddard Space Flight Center in Greenbelt, Md.

Figuring out exactly which molecules are leaving these clues, known as "diffuse interstellar bands" (DIBs), is a puzzle that initially seemed straightforward but has gone unsolved for nearly a hundred years. The answer is expected to help explain how stars, planets and life form, so settling the matter is as important to astronomers who specialise in chemistry and biology as determining the nature of dark matter is to the specialists in physics.

Cordiner is presenting the team's research at the American Astronomical Society meeting in Seattle, Wash., on Jan. 10, 2011, and the results from Andromeda were published in an Astrophysical Journal paper on Jan. 1. The findings provide some evidence against one of the top candidates on the list of suspects: polycyclic aromatic hydrocarbons (PAHs), a group of molecules that is widespread in space. The research also reveals that some of the signatures found in Andromeda and the Triangulum are similar to ones seen in our own Milky Way, despite some big differences between those galaxies and ours.