Posted on: Thursday, November 14, 2002

Hawai'i telescope snaps Io eruption

Associated Press

BERKELEY, Calif. — Astronomers using the Keck II telescope on Mauna Kea have peered across nearly 400 million miles of space to monitor an eruption on Jupiter's moon Io that is the largest ever seen in the solar system.

The massive eruption was photographed Feb. 22, 2001, but the images were only recently processed by an international team led by astronomers from the University of California-Berkeley. The results appear in the November issue of the journal Icarus.

The team used the Keck II telescope on Hawai'i's tallest mountain, itself a dormant volcano, to spy on Io. The moon is the most volcanically active body in the solar system.

The recent eruption spewed lava across 735 square miles.

Scientists used the Galileo robotic spacecraft to monitor Io's volcanoes since it arrived in orbit around Jupiter in 1995. However, Galileo is near the end of its $1.4 billion mission and will plow into Jupiter in September 2003, according to the National Aeronautics and Space Administration.

"It is clear that future monitoring of Io's volcanism lies in the hand of terrestrial observers," said Franck Marchis, a scholar at Berkeley.

The Keck II telescope uses an adaptive optics system that continuously adjusts its multiple mirrors to stabilize and focus the bouncing images created by turbulence in Earth's atmosphere.