Design Filter

The depot will serve as a reserve cache to be brought back to Earth in the event Perseverance is unable to complete the next stage of its mission.

Scientists want rock samples brought home to study in the lab. It will be the best way to determine whether life has ever existed on the Red Planet.

Photos downlinked from the robot on Monday showed the last of the 10 titanium cylinders intended for the depot, lying in the dust between the vehicle's wheels.

Engineers at the University of New South Wales (UNSW) say they have successfully modified a conventional diesel engine to use a mix of hydrogen and a small amount of diesel, claiming their patented technology has cut carbon dioxide (CO2) emissions by more than 85%.

It's the work of Prof Shawn Kook and his team at the university's School of Mechanical and Manufacturing Engineering.

"The interest in converting an existing diesel engine into a clean-burning hydrogen engine is extremely high," Prof Kook tells the BBC at his laboratory in Sydney. Enquiries have come from Germany, South Africa, Brazil, Japan and China.

Nothing on that scale looks like it is about to happen under the area studied by Upflow, fortunately. But it's thought still to be an excellent laboratory.

Its siting was close to the Mid-Atlantic Ridge where some of Earth's tectonic plates meet. The nearby continent of Africa would also influence how plumes would flow. The Upflow team hopes to publish its imagery in the next couple of years.

The project is funded by the European Research Council. Co-principal investigator is Prof Miguel Miranda from the Portuguese Institute for Sea and Atmosphere (IPMA).

"It has the effect that it dampens the waves, and it prevents the breaking of the waves," says founder and chief executive Borge Bjorneklett.

He says that, as the panels are lying completely flat, the forces acting on them are diminished. Being close to the seawater also cools down the cells, which improves their performance.

Both Ocean Sun and SolarDuck are looking at siting solar farms alongside wind turbines, which will smooth the flow of electricity when the wind is not blowing.

River director Dr Lorraine Hawkins stressed the water scooter itself was not the deterrent.

"It's simply the means of us getting the deterrent out towards the seal," she said.

"We've developed this method in consultation with the seal mammal research unit. They're the seal experts and they advise us on how we go about this, so we're confident there's no harm caused to the seal."

The project is being piloted on the Dee until April.