What space telescopes of tomorrow will see

Giant-sized telescopes such as Hubble, Spitzer and Chandra offer unprecedented views of the cosmos, but astronomers are eager to put more powerful tools into orbit around the Earth. Without the extra help, said Rachel Somerville, an astronomer at the Max Planck Institute for Astronomy in Germany, it may be impossible to resolve some of the universe's greatest mysteries. "We need better observations to make our models better," Somerville said, noting her search to understand galaxy formation and mysterious quasars. "... If you just put theorists in a room for the next 15 years with the biggest supercomputer you can find, it will never happen." NASA expects the James Webb Space Telescope (JWST) to launch in 2013, and many scientists are already pondering their future observations of tiny extrasolar planets, elusive black holes and distant galactic arms. Somerville and other astronomers laid bare their sky-watching hopes—including telescopes beyond JWST—at the recent Astrophysics 2020 conference, sponsored by Johns Hopkins University and held at the Space Telescope Science Institute in Baltimore. JWST will boast a segmented mirror nearly 21 feet (6.4 meters) in diameter, which has seven times the light-collecting area of Hubble. Somerville thinks the sensitive infrared observatory will be crucial for understanding galaxy formation. "If you don't have a high enough resolution, galaxies you're trying to observe are going look like fuzzy blobs," Somerville said.

"Seeing the star-filled arms of galaxies in detail, for example, can tell us how some galaxies evolved." And the higher the resolution, the further a telescope can see back in time, as light can take millions or billions of years to reach Earth. While Somerville said NASA's next "great observatory" will deliver unprecedented views of galactic arms, she thinks the telescope could use some help to speed along other cosmic discoveries.