Study of oceans goes beyond Earth

Scientists plan to send probes to moons of Saturn, Jupiter

? The skills and technology used to explore the extreme depths of the Earth’s oceans will soon find work in outer space. Scientists are making plans to probe the icy seas of Jupiter’s moons and drop a lander to the bizarre gasolinelike lakes of Titan, a moon of Saturn.

“The possibilities of studying the extraterrestrial oceans in the solar system is now real,” said Torrence Johnson, a scientist at the Jet Propulsion Laboratory.

Johnson, speaking Saturday at the national meeting of the American Association for the Advancement of Science, said researchers were drawing up plans to send orbiters to Ganymede and Europa. The two Jupiter moons may be covered with oceans under miles-thick layers of ice.

Oceanography, Johnson said, is no longer just an Earth science.

“The universe is awash with water,” he said. “Europa probably contains twice as much water as all of the oceans of Earth.”

Early plans call for orbiting the Jovian moons with craft that can measure tides and penetrate ice with special radar. These are techniques that oceanographers have used to probe the Earth’s waters.

Later plans would mean landing packages on the icy surfaces and perhaps drilling down, searching for liquid water, the most likely domain of life, Johnson said.

Some researchers believe radioactive and tidal heating may form deep reservoirs of liquid water beneath the ice and that life forms may exist there, enduring the extreme pressures and darkness. Oceanographers have found some bacteria living in such conditions in the Earth’s black depths.

Johnson said planetary scientists were leaning on long-tested techniques that oceanographers had used.

A space probe falls toward the surface of Titan in this artist's conception of one of Saturn's moons. Space scientists hope upcoming generations of probes can be sent to explore the oceans of the large, icy satellites orbiting the outer planets.

“We are turning to our oceanographic colleagues who make things work at the unbelievable pressures,” said Johnson.

Studies for the exploration of the oceans of Jupiter’s moons will be completed next year. Johnson said the National Aeronautics and Space Administration would draw up plans for the projects.

Exploration of the surface of Titan, a moon of Saturn, will start even sooner. The Cassini spacecraft, launched seven years ago, will reach Saturn in July and drop a probe to the moon’s surface in January.

Titan, a frigid world about half the Earth’s size, is the only moon in the solar system with a thick atmosphere. Smog generated by a thick nitrogen atmosphere four times denser than the Earth’s obscures Titan’s surface.

“Titan is the largest piece of unexplored real estate in the solar system,” said Ralph Lorenz, a University of Arizona planetary scientist and a leader of the Cassini project.