Pluto and Charon show off two of their sides in pictures taken by the New Horizons spacecraft. Each of the dark spots on Pluto (orange, right) is roughly the size of Missouri.
NASA, JHUAPL, SWRI
RADIO REFLECTIONS To send messages via the moon, ham radio operators send radio waves some 384,000 kilometers to the Earth’s natural satellite. The waves bounce and hopefully are received by a ham radio user somewhere else.
JUMBO-SIZE PLANET Big rocky super-Earths such as Kepler-62f, shown in this illustration, probably don’t have active plate tectonics, new research suggests.