Planetary scientist Jonathan Lunine.

"The amount of things that we can know about the universe is practically infinite," Lunine says. "So by definition, we don’t know anything, or we know zero percent of what’s out there."

Watch the video animation showing Cassini's planned path through the solar system on its way to Saturn.
     

Lunine, 40, is a professor at the Lunar and Planetary Laboratory at the University of Arizona in Tucson. When not thinking about things on a planetary scale, he is an avid hiker and loves auto touring around the desert surroundings. With his wife Cynthia, the two are raising a four-and-a-half-year-old son. "He wants to play poker too," Lunine said.

"The question is, how to become a planetary barfly?," Lunine said. "There’s only a certain amount of things you can do in a certain day. While it seems safe in terms of hedging your bets, it also carries the danger you won’t be well-enough anchored in one field to really get funding. So you strike a balance."

As a man-for-all-planets, he serves on select NASA committees dealing with solar-system exploration and space-science issues.

His passion runs deepest on two fronts: the evolution of those giant celestial objects, brown dwarfs, and extrasolar planet formation; as well as pulling back the cloudy curtain on Saturn's largest moon, Titan.

The Saturn-bound Cassini spacecraft, and its 2004 encounter with the ringed planet, sets Lunine’s speculative mind ablaze. Camera and radar gear on Cassini will bring Titan into sharper focus.

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Also on board Cassini is the European Space Agency-built Huygens probe, a sensor and camera-laden craft built to plunge into Titan’s thick atmosphere. It will send back pictures below the haze, perhaps from a resting spot on solid surface too.

"I think if Cassini works at Saturn and Titan, it will turn out to be a real high point in planetary exploration," Lunine said. "We’re sure to find out that Titan is a very, very fascinating place."

Once released from the Cassini spacecraft in late 2004, the 770-pound (350-kilogram) Huygens probe will streak toward Titan’s surface, slowed down by parachutes. During the descent, instruments on the probe will measure wind speeds, as well as profile temperatures and the makeup of atmospheric gases.

Jonathan Lunine.

Titan is thought to harbor complex organic molecules. It may offer a window into the biochemistry episodes that took place here, on a primitive Earth.

In 1994, the Hubble Space Telescope took the first images of Titan’s surface, showing features underneath the moon’s hazy atmosphere.

"There has been a change of minds about Titan. People no longer think of its surface covered uniformly by some sort of liquid ocean," Lunine said. "The whole idea of a global hydrocarbon ocean has evolved. Maybe there are patches or seas of methane or ethane? We know it has a varied surface."

Lunine believes Titan is a solar system hot spot containing clues about the origin of life. It is a place, he says, where the right stuff for life isn’t 4 billion years old; it's there today.

"If there are lots of liquid hydrocarbons there, lots of organic molecules, then Titan is a place to go back to after Cassini, with better and more sophisticated instrumentation," Lunine said.

To better comprehend life "out there," the key is to take a hard look at the inner workings of how biology was sparked on Earth. "It’s not enough to simply say that we’re just at the right place from the sun," Lunine says.

It is clear that an enormous dance between processes is required to make life.

"These things are so complicated that maybe they don’t work a lot of places elsewhere." On the other hand, perhaps another set of parameters also works well to attain habitability of a planet, he adds.

As if to take his own crash course on the evolution of life, Lunine recently authored Earth: Evolution of a Habitable World, replete with the artistry of his wife, Cynthia.

"Frankly, my study of the Earth doesn’t tell me that we are unique. It simply says that the underlying physical effects that lead to habitability are numerous and extremely complex," says Lunine.

The really earth-shattering discovery yet to come for the general public is finding advanced life somewhere else, Lunine said. "There are an awful lot of surprises left, both in our solar system and, of course, in whatever other solar systems are out there."

In shuffling the cards of life, Lunine said that there’s "plenty of opportunity" for other life to populate the cosmos.