TOPSHOTS The Solar Impulse 2, takes off from al-Bateen airport in Abu Dhabi as it heads to Muscat, on March 9, 2015, in the first attempt to fly around the world in a plane using solar energy. The first attempt to fly around the world in a plane using only solar power launched on March 9 in Abu Dhabi in a landmark journey aimed at promoting green energy. AFP PHOTO / MARWAN NAAMANI