Imagine a plane that crosses continents without burning a drop of fossil fuel. This week, Solar Impulse became the first aircraft to fly between continents powered solely by sunlight, covering the 830km (515 miles) between Madrid in Spain and Rabat in Morocco in 19 hours.
This is definitely not your standard plane. The single-seater craft has the wingspan of an Airbus A340 airliner, but only weighs as much as a passenger car. Its wings are covered with 12,000 photovoltaic cells, which power four electric engines and charge a battery bank for night flight. It is engineered with carbon fibre and other strong but lightweight high-tech materials.
The organisers of the Solar Impulse project say they want to show what can be done with solar power, to inspire more use of clean energy. The flight to Morocco was motivated in part by that country's ambitious plans to harness the blazing Saharan sun to provide 40% of the nation's power by 2020.
Learn more: Read about the Solar Impulse team's plan for a sun-powered flight around the globe in 2014.