Largest solar sail ever to fly in 2014, by a NASA research team In-Space Demonstration of a Mission-Capable Solar Sail. An ultra-thin sail unfurling in space, using the pressure of sunlight to provide propellant-free transport, hovering and exploration capabilities.
Rainbows exhibit the colors we’re all familiar with when they’re not at their highest position in the sky. As the Sun sets, rainbows arch higher and higher without much of change in color. However, once the Sun dips below the horizon, the increased path length of sunlight alters a rainbow’s appearance. Image credit: Phil Thomson; Phil’s Web site