A plane powered entirely by the sun is nearing the end of the world's first solar-powered intercontinental flight. The Solar Impulse left Madrid early this morning, crossed the Strait of Gibraltar, and entered Moroccan airspace, AFP reports. The carbon-fiber plane, which is the size of a jumbo jet but weighs about the same as a car, will eventually land in Rabat, Morocco, the BBC notes.
"The question is not to use solar power for normal airplanes," pilot Bertrand Piccard says. Instead, it's "to demonstrate that we can achieve incredible goals, almost impossible goals, with new technologies, without fuel, just with solar energy, and raise awareness that if we can do it in the air, of course everybody can do it on the ground." Piccard began the Solar Impulse project in 2003; now, the aircraft is preparing for a world tour in 2014. (Read more solar power stories.)