Profs. to use Hubble to study Jupiter

By Susan Luth

Daily Staff Reporter

Four University professors are getting a "once-in-a-lifetime chance" to use new technology and the Hubble Telescope to explore Jupiter in a way it has never been seen before.

This rare opportunity was provided when Cassini, NASA's largest planetary spacecraft, launched last October, flew past Jupiter last week on its way to Saturn.

Cassini carries an instrument called the Cassini Plasma Spectrometer, which was designed by a team led by University atmospheric, oceanic and space sciences Prof. David Young.

Young is using the instrument to measure solar winds as it approaches Jupiter's magnetosphere, the planet's outermost atmospheric layer. Young said his team is searching for a relationship between the winds and the aurora that surrounds Jupiter.

The aurora is an electrical effect of ions and electrons as they collide with a planet's atmosphere. The collision causes a light, and depending on what element or molecule the particles hit, the light becomes different colors.

"The colors are brilliant," Young said. "They look like little halos that sit above the atmosphere."

"We are seeing features in the aurora that we've never seen before," said research scientist John Clarke, a professor in the department of atmospheric, oceanic and space sciences.

Clarke, Young, and atmospheric, oceanic and space sciences Profs. J. Hunter Waite and Tamas Gombosi "are pulling together (their) common interests," Young said.

While Young is studying solar wind from Cassini, Clarke is using the Hubble Telescope to take pictures of the planet's aurora.

The team hopes to match the data from Cassini with the pictures taken by the Hubble.

"We want to see how particles excite the atmosphere and produce the emissions we see," Waite said.

Clarke said he was very fortunate to obtain almost 53 hours of the Hubble's time. Only one in 10 organizations that apply to use the telescope are granted time, Clarke said, and even then they usually receive less than eight hours of time.

Another objective of the mission is to determine the difference between the aurora found on Earth and that of Jupiter.

Jupiter has a diameter 10 times that of the Earth and spins faster. Because Jupiter has a stronger magnetic field than the Earth and has several large moons that give off gas, its effect on the aurora is extremely el to dynamic.

The professors have already received half of the data to be sent by the Hubble and Cassini. Waite and Gombosi, along with several other researchers at the University of Michigan and at University of California at Los Angeles, are placing this data into a mathematical model to determine facts and details about the planet's aurora.

The researchers expect to have a preview of the collected data by the end of this month, with a more extensive understanding of the data in one year at the earliest.

"We are looking at something that's five times the distance from the sun (than Earth)," Clarke said. "The Hubble photos are really spectacular."