Around 30 to 40 million years ago, grasses on Earth underwent an epic evolutionary upheaval. An assemblage capitalized on falling levels of atmospheric carbon dioxide by engineering an internal mechanism to concentrate the dwindling CO2 supply that, like a fuel-injection system in a car, could more efficiently convert sunlight and nutrients into energy.

There seems little doubt that Saturn's moon Enceladus hides a large body of liquid water beneath its icy skin.

The Cassini probe, which periodically sweeps past the little moon, has returned yet more data to back up the idea of a sub-surface sea.

LONDON - Britain's Eco City Vehicles has launched an electric prototype of the Mercedes Vito taxi, which will it trial later this year to test its suitability for use as part of London's iconic black taxi fleet.

"The eVito is the first all-electric wheelchair accessible taxi with a 25-foot turning circle to be launched in the world and a major step toward our goal to become a leading supplier of niche eco-friendly vehicles," said CEO Peter DaCosta.