Galaxy Quests


By Kathy Svitil

Published Jan 1, 2007 8:00 AM

The Outer Limits

Of course, space exploration is not limited just to the planets in our own solar system (whether or not you count Pluto). Explorers are looking all over the cosmos for extrasolar orbs, including Flash Gordon fan Zuckerman, now a UCLA professor of physics and astronomy. Zuckerman is trying to catch an elusive prey: young planets in the making around equally young stars. "We're trying to identify planetary systems that are perhaps analogous to the way our own system looked four and a half billion years ago," Zuckerman says.

Back on Earth, UCLA faculty are working to keep astronauts healthy while in space, through technological advances such as optoelectronic tweezers for handling small objects such as blood cells, bacteria and viruses.

Nearly all extrasolar planets are detected through "wiggles" in their light. The gravitational influence of a large orbiting object will distort the light of the parent star, leaving behind a fingerprint. But Zuckerman isn't satisfied with wiggles. He wants a picture.

In September 2004, Zuckerman was part of a French and American team that obtained images of an object about five times the mass of Jupiter, in orbit around a young brown dwarf named 2M1207, 200 light years from Earth.

"It was the first object of planetary mass imaged in orbit around a star that was not our own Sun. We've now imaged at least one other object that might be a planet, around another star," he says.

We've also imaged unimaginably distant stars themselves. Hansen and his colleagues made their dramatic discovery in the summer when they spied a collection of faint, old stars, nearly as ancient as the universe. Using the Hubble Space Telescope, Hansen discovered the dim cluster of stars, NGC 6397, 8,500 light years from Earth. The faintest stars we have been able to see are an estimated 12 billion years old. That's just 1.7 billion years younger than the universe itself, according to measurements released in 2003 by Edward Wright, UCLA professor of physics and astronomy, and his colleagues on NASA's Wilkinson Microwave Anisotropy Probe (WMAP) team.

In addition to his work on WMAP, Wright is the principal investigator of NASA's Wide-field Infrared Survey Explorer (WISE), an ambitious, $300-million orbiting telescope that will scan the whole sky in infrared wavelengths, looking for distant and luminous galaxies, perhaps as much as 11.5 billion years old, planetary construction zones, brown dwarfs (the faintest stars) and, possibly, evidence of dark energy — the mysterious force, first postulated by Albert Einstein, believed to make up 73 percent of the universe.