Spacecraft managed by JPL for NASA have visited every planet in our solar system. This daunting accomplishment began when the JPL-built Mariner 2 spacecraft flew past Venus in 1962. Since then, many NASA space missions have explored the other planets and some of their many moons, as well as asteroids and comets.These missions have brought us dramatic and diverse discoveries, including volcanoes, canyons, geysers, colossal storms, and evidence of liquid oceans on other worlds.The venerable twin Voyager spacecraft have played a pivotal role in unlocking solar system secrets.