Spitzer Finds Life Components In Young Universe

Using Spitzer, scientists have detected organic molecules ingalaxies when our universe was one-fourth of its current age of about14 billion years. These large molecules, known as polycyclic aromatichydrocarbons, are comprised of carbon and hydrogen. The molecules areconsidered to be among the building blocks of life.

These complex molecules are very common on Earth. They form any timecarbon-based materials are not burned completely. They can be found insooty exhaust from cars and airplanes, and in charcoal broiledhamburgers and burnt toast.

The molecules, pervasive in galaxies like our own Milky Way, play asignificant role in star and planet formation. Spitzer is the firsttelescope to see these molecules so far back in time.

"This is 10 billion years further back in time than we've seen thembefore," said Dr. Lin Yan of the Spitzer Science Center at theCalifornia Institute of Technology in Pasadena, Calif. Yan is leadauthor of a study to be published in the August 10 issue of theAstrophysical Journal. Previous missions -- the Infrared AstronomicalSatellite and the Infrared Space Observatory -- detected these types ofgalaxies and molecules much closer to our own Milky Way galaxy.Spitzer's sensitivity is 100 times greater than these previous infraredtelescope missions, enabling direct detection of organics so far away.

Since Earth is approximately four-and-a-half billion years old,these organic materials existed in the universe well before our planetand solar system were formed and may have even been the seeds of oursolar system.

Spitzer found the organic compounds in galaxies where intense starformation had taken place over a short period of time. These "flash inthe pan" starburst galaxies are nearly invisible in optical imagesbecause they are very far away and contain large quantities oflight-absorbing dust. But the same dust glows brightly in infraredlight and is easily spotted by Spitzer.

Spitzer's infrared spectrometer split the galaxies' infrared lightinto distinct features that revealed the presence of organiccomponents. These organic features gave scientists a milepost to gaugethe distance of these galaxies. This is the first time scientists havebeen able to measure a distance as great as 10-billion light years awayusing the spectral fingerprints of polycyclic aromatic hydrocarbons.

"These complex compounds tell us that by the time we see thesegalaxies, several generations of stars have already been formed," saidDr. George Helou of the Spitzer Science Center, a co-author of thestudy. "Planets and life had very early opportunities to emerge in theuniverse."

Other co-authors include Ranga-Ram Chary, Lee Armus, Harry Tepliz,David Frayer, Dario Fadda, Jason Surace, and Philip Choi, all of theSpitzer Science Center.

The Jet Propulsion Laboratory manages the Spitzer Space Telescopemission for NASA's Science Mission Directorate, Washington. Scienceoperations are conducted at the Spitzer Science Center at Caltech.Caltech manages JPL for NASA. Spitzer's infrared spectrograph was builtby Cornell University, Ithaca, N.Y. Its development was led by Dr. JimHouck of Cornell.

The Infrared Astronomical Satellite was a joint scientific projectsponsored by the United States, the Netherlands, and the UnitedKingdom. The Infrared Space Observatory was a European Space Agencymission with Japan's Institute of Space and Astronautical Science andNASA.

For information on the Spitzer Space Telescope visit: http://www.spitzer.caltech.edu/Media .

For more information on NASA missions and programs visit: www.nasa.gov .