Cassini Beams Saturn Images Across 934 Million Miles

PASADENA, California, July 2, 2004 (ENS) - The space mission Cassini-Huygens paid off 20 years of work in a big way on Thursday when the scientific team at NASA's Jet Propulsion Laboratory saw the first images of Saturn's rings.

The Cassini spacecraft transmitted the pictures across 934 million miles of space just hours after it slipped through the rings Wednesday night, entering an orbit around the planet to begin a four year study.

Delighted Cassini scientists called images of the rings "dramatic" and "mind-boggling."

View of Saturn's rings taken by a camera aboard the Cassini spacecraft. (Photo courtesy NASA/JPL/Space Science Institute)

Cameras aboard the spacecraft moving about 34,000 miles per hour caught close-ups of the rings in black and white.

"We won't see the whole puzzle, only pieces, but what we are seeing is dramatic," said Dr. Carolyn Porco, Cassini imaging team leader from the Space Science Institute in Boulder, Colorado. "The images are mind-boggling, just mind-boggling. I've been working on this mission for 14 years and I shouldn't be surprised, but it is remarkable how startling it is to see these images for the first time."

Some images show patterned density waves in the rings, resembling stripes of varying width. Another shows a ring's scalloped edge. "We do not see individual particles but a collection of particles, like a traffic jam on a highway," Porco said. "We see a bunch of particles together, then it clears up, then there's traffic again."

Three density waves in Saturn's A ring in an image taken from inside Saturn's orbit. The view shows the dark, or unlit, side of the rings. (Photo courtesy NASA/JPL/Space Science Institute)

One instrument aboard is designed to record images of Saturn's magnetosphere, a bubble of energetic particles around the planet shaped by Saturn's magnetic field and surrounded by the solar wind of particles speeding outward from the Sun. The instrument showed that Saturn's magnetic field pulsed in size as Cassini approached.

Three U.S. spacecraft have visited Saturn briefly in the past. The Pioneer, Voyager 1 and Voyager 2 spacecraft flew past the planet in 1979, 1980 and 1981.

"With Voyager we inferred what it looked like, in the same way that a blind man feels an elephant. Now we can see the elephant," said Dr. Tom Krimigis of Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, principal investigator for the magnetospheric imaging instrument.

One of the first images taken of Saturn's F ring by the Cassini spacecraft after it entered Saturn's orbit (Photo courtesy NASA/JPL/Space Science Institute)

On January 14, 2005, the Huygens probe will enter Titan’s dense atmosphere, deploy its parachutes and begin its scientific observations during a descent that could take two and a half hours.

If the probe survives landing at about 15 miles per hour, it can possibly return data from Titan’s surface, where the atmospheric pressure is 1.6 times that on Earth. NASA scientists say the probe could touch down on solid ground, ice or in a lake of ethane or methane.

One instrument on board can tell whether Huygens is bobbing in liquid, and other instruments on board would identify its chemical composition. Huygens will radio all data collected by its instruments to the Cassini orbiter to be stored and sent on to Earth.

Launched October 15, 1997 from Cape Canaveral, Florida, the Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Office of Space Science in Washington, DC. The Jet Propulsion Lab designed, developed and assembled the Cassini orbiter.

Celebrating Cassini's arrival at Saturn, Dr. Charles Elachi, director of NASA's Jet Propulsion Laboratory, high fives Cassini Program Manager Robert Mitchell, left. Dr. Ed Weiler, NASA's associate administrator for space science, looks on at right. (Photo courtesy NASA/JPL)

Cassini is powered by 72 pounds of plutonium that has been the subject of protest and debate by people concerned that mission failure would release the radioactive substance into Earth's atmosphere, contaminating hundreds of thousands of people around the world.

Since the 1960s there have been eight space nuclear power accidents by the United States and the former Soviet Union, several of which released plutonium into Earth's atmosphere. In April 1964 a U.S. military satellite with 2.1 pounds of plutonium-238 on board fell back to Earth and burned as it hit the atmosphere, spreading plutonium dust.

Saturn is the sixth planet from the sun, the second largest planet in the solar system, after Jupiter. The planet and ring system are a miniature model for the disc of gas and dust surrounding the early Sun that formed the planets.

Communications with Cassini during the mission are carried out through stations of NASA’s Deep Space Network in California, Spain and Australia. Data from the Huygens probe will be received and relayed by the network and sent to the European Space Agency operations complex in Darmstadt, Germany.

NASA scientists say detailed knowledge of the dynamics of interactions among Saturn's rings and moons will provide valuable data for understanding how each of the solar system's planets evolved.

For the latest images and more information about the Cassini- Huygens mission, visit http://saturn.jpl.nasa.gov and http://www.nasa.gov/cassini.