Editor’s note:
Star science reporter Dan Sorenson and higher education reporter Eric Swedlund have spent two months researching and reporting for a three-day series about space sciences at the University of Arizona and across the state. The Star’s three-day special report begins Sunday, complete with exclusive online-only content. Along the way our reporters interviewed dozens of scientists in Tucson, Tempe and Flagstaff and as a preview to the series, will introduce you to some of the researchers, programs and missions daily on this blog.

The Arizona Radio Observatory is on the lookout for primitive organic molecules in the cold, dense gas clouds of interstellar space.

“People think of astronomy as just looking at stars,” says Lucy Ziurys, the lab’s director. But her work is to detect and study molecules in space, using spectroscopy and modeling to determine which chemical compounds are out there. About 140 different compounds have been discovered in interstellar space of our galaxy, and more basic studies of other galaxies have discovered about 30 of the simplest compounds.

Scientists think all carbon on Earth came from interstellar space, from comets and meteorites crashing into the planet, and Ziurys is on the lookout for where else these organic chemicals are.
The UA has two radio telescopes at its disposal, one of few universities in the country to have its own. The Submillimeter Telescope on Mount Graham is the world’s most accurate radio telescope and the 12 Meter Telescope on Kitt Peak gave birth of millimeter-wavelength molecular astronomy. Dozens of molecular species known to exist in the interstellar medium were first detected using the 12 Meter Telescope.

Not bad for a field that’s barely 30 years old.

“Forty years ago, people said molecules couldn’t exist in interstellar space, period,” says Ziurys, a member of the NASA Astrobiology Institute. “Now 50 percent of the matter in our galaxy is thought to be molecular in nature. We’re just beginning to scratch the surface of the molecular content that’s out there.”

The molecules are found in big gas clouds in our galaxy and others, in the densest and coldest parts of interstellar space, areas that are passed over by infrared and optical astronomy, which examine hotter regions of space.

“It’s complementary because we’re looking at matter others can’t even see,” Ziurys says.

These giant gas clouds eventually collapse into stars, solar systems and planets, or conversely, are the result of gas being blown into space by dying stars.

“We’re looking at solar systems that haven’t formed yet, or are forming,” Ziurys said, with the goal of finding clues that lead to a better understanding of the origins of our solar system.

Radio astronomy’s next big advances will arrive with the Atacama Large Millimeter Array, a single instrument made of dozens of high-precision 12-meter antennas that will be placed on a 16,400-foot mountain top in Chile. A broad international collaboration is behind the ALMA, set to start in 2012, which will offer a whole order of magnitude improvement over the current detectors.

The ALMA technology, however, is already being used by the UA, which a year ago put the more sensitive detectors on one frequency band of its telescopes and is already seeing more complex organic compounds, Ziurys says.

“The question is how complex interstellar organic molecules are,” Ziurys said. “Can it lead to things biochemically important for life?”
Ziurys’ team has discovered two compounds extremely important to biochemistry — phosphorus monoxide and glycol aldehyde, a well-known precursor to ribose, the sugar molecule that forms the backbone of DNA and RNA.

Ziurys thinks pre-biotic compounds and DNA itself may even be present in these interstellar gas clouds, though the sensitivity of detectors is far from able to detect it yet.

“We talk about whether there’s life elsewhere in our galaxy and the chemistry suggests there is,” she says.