The Cassini-Huygens spacecraft orbiting Titan, Saturn's largest moon, will release a lunar probe on Christmas day that will penetrate the mysterious moon's thick atmosphere and be the first to land on a world in the outer solar system.
UA professor Jonathan Lunine, one of the interdisciplinary scientists working on the mission, described Titan as, "the last unexplored Earth-like environment."
"I think it will be an incredibly exciting and rewarding world to study," Lunine said.
NASA, along with several UA scientists and the European Space Agency, are communicating with the Cassini orbiter from a distance of a little more than 2 billion miles to ensure the release of its piggybacking Huygens probe is properly timed.
The probe will plunge into Titan's atmosphere at 14,000 miles per hour on Jan. 14, 2005, and will use parachutes to slow its descent to the surface, said Jean-Pierra Lebreton, Huygens project manager at the European Space Agency.
There have never been any high-resolution images of Titan's surface due to a thick photochemical fog which makes the moon appear reddish-orange to the naked eye. Even the Cassini orbiter's instruments, including radar, the UA-created Visual and Infrared Mapping Spectrometer and its camera, have trouble getting an image resolution tighter than a kilometer, said Martin Tomasko, research professor at the UA Lunar and Planetary Laboratory.
The Cassini-Huygens team hopes the probe will survive the landing, which Tomasko, who has worked with the Cassini-Huygens team since 1987, likens to "riding your bicycle into a brick wall."
Lunine, a theoretician, said data collected by the Huygens probe would likely provide more clues about the origin of life. The Cassini-Huygens mission has already discovered stores of organic molecules on Titan, including water, oxygen, methane and carbon.
However, Lunine said temperatures colder than minus 300 degrees Fahrenheit prevent the creation of conventional life forms on Titan.
Referring to images taken of Titan's surface by the Visual and Infrared Mapping Spectrometer, Lunine pointed to dark patches of what is theorized to be "organic goo."
"It is our hope that the probe will land someplace dark," he said.
This "goo," which may be rich in organic molecules, should provide the best field for origin-of-life research, Lunine said.
As the Huygens probe descends to Titan's surface, its Descending Imager Spectral Radiometer (DISR), also put together by a UA team, will snap photographs.
The DISR cameras will compile images into 20 panoramas, each consisting of 36 different images taken from different altitudes, said Tomasko, the principal investigator of the DISR. The first panoramas will be taken at 150 kilometers from Titan's surface, and the last panorama, taken within feet of the ground, will show objects that are just inches across. If the probe survives its landing, it will also take pictures of Titan's surface itself.
The DISR will also measure the flow of sunlight in Titan's atmosphere, which will tell scientists about the nature of atmospheric aerosols, the vertical distribution of the photochemical haze, the abundance of methane and how sunlight heats the planet.
"There's quite a number of scientific objectives that we think we can achieve that have not been possible with other instruments," Tomasko said.
Lunine said there were several UA undergraduate, graduate and post-doctoral students involved with this year's Cassini-Huygens team working on various projects headed by UA Lunar and Planetary Lab scientists.
"Some of our undergraduate students (who worked on Cassini-Huygens) have become so successful, I must say, that we see them on TV directing their own missions," Lunine said.
Tomasko said the technology being developed at the UA will likely be used in mankind's future interplanetary probe missions.