We know more about the far side of the Moon than we do about much of the deep sea. This is because much of the deep ocean is opaque to our senses; radio waves quickly attenuate (die away).

In order to learn more about the deep ocean, a US team is this weekend laying 52km of thick electrical cable from a research station on shore to a shelf 900m in below the sea's surface - in Monterey Canyon. Monterey Canyon is the largest and deepest submarine canyon off the continental West Coast of the United States. The shelf concerned is known as Smooth Ridge.

On the map above, MBARI is the research institute undertaking the project and located on shore. MARS is the proposed underwater laboratory and will sit on the underwater shelf (Smooth Ridge).

The cable will connect MBARI PCs with MARS underwater research instruments). The purpose of this cable is to:

• send power to the instuments;
• return data from the instuments to the PCs.

(MBARI is short for Monterey Bay Aquarium Research Institute. MARS is short for Monterey Accelerated Research System. The instruments being set up this week are actually only the first phase of MARS.)

Above is a computer-generated perspective view of Monterey (undersea) Canyon. (Compare the shapes with those on the map on the left.)

The ocean plays a critical role in climate regulation because of its ability to store heat and carbon. It is also host to other environmental problems, such as the decline of fisheries and the bleaching of coral reefs.

Scientists think that 10 years from now there may be as many as 10 big undersea cabled networks around the world similar to the Monteraey Canyon one.

The main MARS cable - most of it is buried in the seafloor to minimise disturbance to marine life - will connect to a large central hub, or node, on Smooth Ridge.

The hub is similar in function to an office multi-plug power point, but the size of a small car and weighing six tonnes.

MARS's main science node sits at a depth of almost 900m. Running off the node will be a series of instruments that constantly return data to shore.

MARS will have its own rover. Later this year, a remotely operated vehicle (ROV) will begin to plug the instruments into the ports. A human pilot, using a joystick and the ROV cameras as eyes, will guide the robot's mechanical arm from the ship above.

If you find connecting a desktop computer to the network frustrating, imagine doing it in water in the dark - and under 17 megapascals of pressure!

The enormous canyon system begins just 50m (160ft) off this beach.

Mars will encounter animals like the "rattail", or Pacific grenadier.