for National Geographic News
The Cassini spacecraft is set to buzz through the upper atmosphere of Saturn's moon Titan on Tuesday. If all goes according to plan, the probe will use high-tech cameras during the flyby to peer through Titan's hazy orange atmosphere and peek at the moon's mysterious surface.
"This is the first good look at Titan," said Dennis Matson, project scientist for the Cassini-Huygens Mission to Saturn and Titan at NASA's Jet Propulsion Laboratory in Pasadena, California.
Titan has long intrigued scientists. Its surface and atmosphere are thought to resemble that of Earth several billion years before life as we know it began pumping oxygen into the atmosphere.
Cassini came within 210,600 miles (339,000 kilometers) of Titan on July 2, days after it entered orbit around Saturn. The spacecraft will fly by Titan at an altitude of 746 miles (1,200 kilometers) on Tuesday, the first of more than 40 planned close encounters.
Scientists say that at such an altitude, the moon would appear as a featureless, fuzzy, beige ball to the naked eye, given the celestial body's hazy upper atmosphere and uniform cloud cover.
"However, Cassini is equipped with a suite of instruments that will allow us to peer through the atmosphere and reveal the surface," said Carl Murray, a member of the Cassini imaging team and professor of mathematics and astronomy at Queen Mary University of London in England.
The Cassini-Huygens mission is a joint project of NASA and the European Space Agency.
Images taken during the spacecraft's flyby will enable scientists to begin answering questions about Titan's surface, atmosphere, and chemical composition.
Does the moon have oceans and lakes of liquid methane? Is Titan covered with mountains of ice? Is the moon pockmarked with impact craters? Cassini-Huygens's July 2004 flyby only hinted at answers to such questions.
"At this point, it is way too early to tell what features we are seeing on the surface. But it doesn't look simply like a cratered surface," said Elizabeth Turtle, a planetary scientist at the University of Arizona in Tucson.
SOURCES AND RELATED WEB SITES