TEMPE, ARIZONA -- A high-tech approach to ocean exploration will not only provide insight into the origin of life on Earth but how to search for life on other worlds.

Called Project Neptune, the plan is to convert the Juan de Fuca tectonic plate in the northeast Pacific Ocean and the overlying sea into a suite of undersea observatories. An armada of nautical hardware, including autonomous rovers, would be part of an oceanic toolkit to probe a range of Earth and ocean processes.

On the scientific study agenda: Monitor submarine volcanoes, home to a bizarre and uncharted biosphere of microbes that thrive on heat and chemicals bubbling up from deep within the Earth.

Neptune calls for some 1,900 miles (3,000 kilometers) of fiber-optic power cables to encircle and cross the Juan de Fuca plate, off the U.S. and Canadian west coasts. A tectonic plate is a massive, irregularly shaped slab of solid rock, generally composed of both continental and oceanic lithosphere, the outer layer of the Earth which is cool enough to behave as a more or less rigid shell.

The Juan de Fuca slams into surrounding crustal plates and is a point of origin for many powerful earthquakes that rattle the West from northwestern California northward. All the activity also releases heat and chemicals into the sea at prolific rates.

Once the area is wired for science, the network itself will cover an region roughly 310 miles by 620 miles (500 kilometers by 1,000 kilometers) in size. More than two dozen experimental sites will form nodes along the sub-sea cable system. Nodes will be situated about 62 miles (100 kilometers) apart.

Each of the nodes would be outfitted with scientific instruments. Suites of sensors and other gear are being designed to interact with physical, chemical, and biological phenomena on, above, and below the sea floor. They'll look at water column processes, carry out seismology duties and study marine mammals and deep-sea ecology.

Added to the mix are remotely operated and autonomous undersea vehicles. These "aquacraft" hook up to the underwater nodes for recharging, enabling them to be on-call for events such as submarine volcanic eruptions.

Experts at NASA's Jet Propulsion Laboratory in Pasadena, Calif. have played a key role in coming up with innovative ways to power and distribute energy throughout the undersea network. Other partners in the venture include the Woods Hole Oceanographic Institution, the Monterey Bay Aquarium Research Institute, the University of Victoria, and Canada's Institute for Pacific Ocean Science and Technology.

The Neptune infrastructure is expected to operate for more than 30 years. Once in place, scientists will have a real-time command-and-control ocean exploration network at their fingertips, operating 24 hours a day, 7 days a week via high-speed Internet communications link.

Neptune will appear as a seamless extension of the global Internet, connecting users anywhere on shore to the sensors on the seafloor.

"It's almost a Zen-like thing. We are looking inward in order to figure out how to look outward," said John Delaney, leader of the Neptune project and professor at the University of Washington's School of Oceanography in Seattle.

"We clearly are going to have to explore worlds that have water on them…and a lot of water in some cases," Delaney told SPACE.com. "Something like Neptune allows us to get started now in developing the kinds of sensors that have to be eventually exported off the planet," he said.

Delaney detailed Neptune during the NASA Astrobiology Institute General Meeting, held here Feb. 10-12 and hosted by Arizona State University. Astrobiology is the study of life in the universe, both terrestrial and extraterrestrial.

The ocean exploration project can give technologists a leg up on setting down probes on faraway places, like Europa. This moon of Jupiter is believed to harbor an ocean below its icy face.

Future scientific packages bound for deep diving on Europa must undergo extensive trial runs before being lofted off Earth. And Project Neptune offers the chance to ring out both hardware and procedures, Delaney said.

"One of the most dependable techniques of establishing that there's life is to have your sensor package eaten by it," Delaney said, smiling. "But beyond that, there are really complicated questions and issues that need to be addressed before dropping a probe into the ocean on Europa."

For astrobiologists, the Earth's ocean offers a watery window to searching for life in outer space. In particular, how Earth's hydro-geochemical systems support life without sunlight on the seafloor is a central research question. Furthermore, ocean exploration can help gauge the limits and origins of life.

"Neptune provides a way for us to explore extreme environments that have basic scientific interest to astrobiology," said Michael Meyer, astrobiology senior scientist at NASA Headquarters in Washington, D.C.

Hydrothermal vents may well be the site for the origin of life, Meyer said. Observing the chemistry that goes on in undersea vents is invaluable, he said, as is looking for the hardiest and weirdest organisms percolating up from these escape valves.

While NASA has yet to fully commit itself to the Neptune project, Meyer said that the ability to test robots assigned astrobiological tasks is appealing. Think-for-yourself probes on Mars and Europa are critical to the future space exploration agenda, he told SPACE.com.

"If we are ever going to expand the information that we get back from exploring planetary surfaces, we have to have robot platforms that make active decisions on their own," Meyer said. "As long as we stay in a babysitting mode with robots, the data rates and measurements are going to be very slow and low."

Delaney said that the multi-phased Neptune effort could get wet around 2007. Already plotted out are several cabled observatory test beds -- sites that can hammer out methods and hardware for a larger Neptune system.

MARS (the Monterey Accelerated Research System) and VENUS (the Victoria Experimental Network Under the Sea) are nearshore observatories under development in the United States and Canada. These sites serve as proof-of-concept tryouts for cabled observatories like Neptune.

MARS and VENUS will test the technology to be used at cabled observatories and will allow scientists to develop and test many of the experiments that could eventually be deployed on Neptune. The VENUS work has been funded by the Canada Foundation for Innovation. The U.S. National Science Foundation (NSF) has provided money for MARS.

The cost for creating, installing, and running Neptune for the first five years is approximately the tally of a NASA Discovery spacecraft mission -- in the ballpark of $150 million to $200 million. Operating costs are estimated at $10 million to $15 million per year. To date, funding to help move Neptune into reality has come from government and private sources, with raising funds as a continuing high priority effort within the project.

"Hard-wired to the Internet, Neptune will enable a new paradigm where ocean and earth investigations can be conducted for decades from instrument arrays immersed in the dynamic environments within and beneath our oceans," Delaney reported at the astrobiology meeting. "It’s a Hubble telescope for inner space."

Delaney said elements of the ocean exploration network are adjustable and can be altered, expanded, or rearranged. Robots cruising around the network offer the ability to rapidly respond to undersea happenings. Be it underwater earthquakes, blue whales migrating, or microbes spewing out of erupting volcanoes -- these type of intermittent events can be surveyed.

"Neptune will give us access to an incredible spectrum of both esoteric and pragmatic investigations," Delaney said, "of what is effectively the medium from which life probably sprang, which is the ocean."

Delaney refers to the ocean exploration undertaking as a "fiber-optic telescope to inner-space." But Larry Mayer, director of the Center for Coastal and Ocean Mapping at the University of New Hampshire, sees it differently. "To me the analogy is the space station…the infrastructure that will allow us to deploy a range of experiments, planned and not yet imagined, for years to come," Mayer suggests in a recent Neptune Update newsletter.

"When you think about this deeply for a long time, you realize that the ultimate legacy of this work will be the skills we develop, the insights we gain, and the archives we collect. That's the payoff," Delaney concluded.