Astronomy Picture of the Day

Explanation: Daedalus warned Icarus that if he flew too high, the Sun would melt his wings. Apparently, nobody gave the ERAST Pathfinder-Plus aircraft a similar warning. Earlier this month, not only did Pathfinder-Plus fly higher than any previous propeller-driven aircraft - its wings converted sunlight into power. Pictured, Pathfinder-Plus is flying above Hawaii soon after soaring to a record height of 24,700 meters. What's more, Pathfinder-Plus is only a prototype -- future aircraft in the ERAST program may fly higher. Pathfinder's wings spread nearly 30 meters, and its total mass is only about 270 kilograms. NASA's Pathfinder-Plus is flown by remote control, and can stay aloft for weeks at a time.