Dr Paxton has eschewed sonar detectors, underwater cameras and robot submarines in favour of an entirely different method of detection: statistics.

ECONOMIST: Statistics

Ian Roxburgh, professor of astronomy at Queen Mary, University of London, said the transit method still favoured the detection of big planets, because they blocked out more light from the parent star.

BBC: Telescope sees smallest exoplanet

But the method favours the detection of large planets orbiting close to its parent star.

BBC: Telescope sees smallest exoplanet

The NIR method is highly specific for the detection of different kinds of fatty acids and it is intended to develop a database of fingerprints for different fatty acid components in algal biomass, with which to analyse actual algae.

FORBES: Looking For Algal Oil With Near Infrared Light

There are a few drawbacks to the mouse-method though, as the release of vapor from mines can depend on conditions in the ground, leading to detection some meters from the actual device, or no detection at all.

ENGADGET: Alt-week 27.10.12: ancient texts, super-Earths and special-ops mice