Astronomers seek cosmic 'building blocks'

CAMBRIDGE, Mass., Sept. 14 (UPI) -- Scientists say a search for the "building blocks" of the solar system has proved fruitful as they've added new objects to their cosmic inventories.

Icy rocks beyond the orbit of Neptune are known as trans-Neptunian objects. Pluto, now classified as a dwarf planet, is one of the largest. Halley's Comet is another. All are small and receive little sunlight, making them faint and difficult to spot, astronomers at the Harvard-Smithsonian Center for Astrophysics say.

But examining data from NASA's Hubble Space Telescope has added 14 new TNOs to the catalog, with the promise of finding hundreds more, they say.

"Trans-Neptunian objects interest us because they are building blocks left over from the formation of the solar system," Cesar Fuentes, formerly with the Harvard center and now at Northern Arizona University, said.

Using software to examine hundreds of long-exposure Hubble images, scientists have begun identifying new TNOs, most with diameters of between 25 to 60 miles.

Their initial study examined only one-third of a square degree of sky, leaving much more area to survey. Hundreds of additional TNOs may lurk in the Hubble image archives, scientists say.