Article Posted on : - Jun 18, 2010

Artist's concept of Cassini's flyby of Saturn's moon Titan. The spacecraft flies to within 880 kilometers (547 miles) of Titan's surface during its 71st flyby of Titan, known as

PASADENA, Calif. (BNS): NASA's Cassini spacecraft will take its lowest dip through the hazy atmosphere of Saturn's moon Titan on June 21.

The flyby on early morning of June 21 UTC, which is the evening of June 20 Pacific time, will take the spacecraft 70 kilometers (43 miles) lower than it has ever been at Titan before, NASA JPL said in a statement.

The Cassini mission this weekend will try to establish if Titan, Saturn’s largest moon, possesses a magnetic field of its own.

"For Titan scientists, this is one of the most anticipated flybys of the whole mission. We want to get as close to the surface with our magnetometer as possible for a one-of-a-kind scan of the moon," said Cassini team scientist, César Bertucci.

Flying at this low altitude will mark the first time Cassini will be below the moon’s ionosphere, a shell of electrons and other charged particles that make up the upper part of the atmosphere.

As a result, the spacecraft will find itself in a region almost entirely shielded from Saturn’s magnetic field and will be able to detect any magnetic signature originating from within Titan.

This is important for understanding the moon’s interior and geochemical evolution, the scientist said.

Titan orbits within the confines of the magnetic bubble around Saturn and is permanently exposed to the planet’s magnetic disturbances.

Previous measurements by NASA’s Voyager spacecraft and Cassini at altitudes above 950 kilometers (590 miles) have shown that Titan does not possess an appreciable magnetic field capable of counterbalancing Saturn’s.

“However, this does not imply that Titan’s field is zero. We’d like to know what the internal field might be, no matter how small,” he said.