Mars rover gets instructions daily from NASA via a network of antennae The Washington Post

We live in a chaos of electromagnetic energy. Visible, infrared and ultraviolet light courses omnidirectionally from the sun. A fraction of it bathes our planet, while some bounces off other planets, moons, comets and meteoroids. The visible light from stars up to 4,000 light-years away can be seen from Earth with the naked eye. With instruments, astronomers can detect gamma rays from stars 13 billion light-years away. Radio waves from remote galaxies help Earth’s official timekeepers monitor our planet’s path around the sun.
Once per day, a minuscule stream of radio waves joins this cacophony, making the 13.8-minute trip from an antenna on Earth to an SUV-size machine parked on the surface of Mars. Those short-lived waves represent our way — our only way — of communicating with Curiosity, the rover that NASA landed on Mars in August.