Scientists will learn plenty about Saturn
Published Friday, November 14, 2003 10:42:36 AM Central Time
By DONN WILLIAMS
EagleHerald staff writer
dwilliams@eagleherald.com
MENOMINEE -- When the Cassini-Huygens spacecraft arrives at Saturn next July to begin the exploration of the ringed planet and its moon Titan, Planetary Scientist Kevin Grazier expects to see more mysteries of the universe revealed.
Grazier works at NASA's Jet Propulsion Laboratory in Pasadena, Calif. He is a member of the imaging team on the Cassini-Huygens mission.
He was in Menominee this week speaking to students and teachers in local schools about that mission and other recent developments in the study of the solar system.
Grazier is one of six scientists and educators here as part of the Journey Through the Universe program, conducted by NASA and the Challenger Center for Space Science Education in Washington D.C.
The Cassini probe was launched into space from Florida in October 1997.
The nearly seven-year flight of the two-story tall space probe to Saturn is a scientific feat in itself. "When we have a spacecraft that big, we cannot build a booster rocket big enough to send it directly to Saturn," Grazier explained.
Because of that, a scientific technique called "gravity assist" had to be employed. "Following launch into the inner solar system, (the probe) swung past Venus and picked up speed. That got it over to Mars. Then it fell back, and again passed Venus and Earth," Grazier said. "Each time it swings by, we pick up speed to allow the probe to 'slingshot' to the outer solar system."
On its way to Saturn, the Cassini probe passed Jupiter. It was able to perform numerous scientific experiments and send back spectacular images of the monstrous planet that is a ball of gas and clouds.
Cassini was able to provide much more data than the ill-fated Galileo spacecraft that has orbited Jupiter since 1995, Grazier said. Three parts of the main antenna on Galileo failed to open when it began to orbit Jupiter, slowing the rate data could be sent back to Earth.
"We were able to recover atmospheric movies with Cassini that Galileo was unable to do," Grazier said. "One thing we did learn was that Jupiter's magnetic environment is much bigger than we originally thought. It's the largest structure in the solar system."
The Cassini probe also provided scientists with an image of a volcano erupting on Io, one of Jupiter's moons. It is the most volcanically active body in the solar system, Grazier said.
Now the Cassini probe is on its way to Saturn, where on July 1, 2004, it will cross Saturn's ring plane and enter orbit around the planet.
Here Cassini will study the complex magnetic environment of Saturn and its stunning rings.
"To me the most interesting things are the rings," Grazier said. "There are rings you can see and there is a huge ring outside that you can't see. It's micron size ice crystals."
Ice crystals in the cold temperatures of space are as hard as granite, but they exist just a short time before they turn into a gas, Grazier said.
Because this ring of ice has been there a long time, Grazier is hoping information from the Cassini probe will shed some light on speculation a volcano on one of Saturn's moons spews out ice crystals that create this ring.
The Huygens probe that is being carried "piggy-back" on Cassini to Saturn will detach from the orbiter on Christmas Day 2004 and parachute onto the moon Titan 22 days later.
Titan is Saturn's only moon with atmosphere. "That atmosphere we believe is very similar to the atmosphere that gave rise to life on Earth, even through Titan is probably too cold to have life," Grazier said.
Titan remains the largest unmapped solid surface in the solar system, because thick orange clouds surrounding it, hide its surface.
Grazier is hoping filters on imaging cameras on board the Huygens probe will help scientists see through the clouds when it lands. If they don't work, radar will be bounced off the surface of Titan to create a visual map of the landscape.
"I'm looking forward to seeing what Titan looks like," Grazier said. "We think on the surface there are lakes of ethane or methane -- potentially liquid natural gas. This is a big question mark."
A lull in his busy scheduled allowed Grazier to take part this week in the Journey Through the Universe program in the Menominee schools.
In addition to his work with NASA, Grazier teaches college astronomy and narrates planetarium presentations at the famed Griffith Observatory in Los Angeles.
He also dabbles in the Hollywood entertainment industry. Grazier has done freelance writing for the television program "Star Trek: Voyager." He's served as science advisor and actor in "Battlestar Galactica: The Second Coming" due to be seen on the Sci Fi channel next month
[LOL! - Peter]. And he helped write a new science fiction series "The Great War of Magellan" that he's hoping a Hollywood studio will pick up.
Despite all of these other interests, his work with the Jet Propulsion Laboratory remains his first priority. Next month Grazier will return to work in earnest on the Cassini-Huygens mission. "It will be 60- to 80-hour work weeks for a while," he said.