Environment Health: A plane powered only by the Sun has completed the first leg of a journey that aims to cross the US.
Solar Impulse, as the vehicle is known, took off at dawn from San Francisco, California, on Friday and landed in Phoenix, Arizona, some 18 hours later.
The craft will stop over in Dallas, St Louis, Washington DC and New York in the coming weeks.
The plane has the same wingspan as an Airbus A340 but it weighs just 1.6 tonnes.
It has already made a day-and-night flight lasting more than 26...