Juno Spacecraft Shaves the Earth on Its Way to Jupiter

The Juno spacecraft was launched on August 2011, and it's taking the long road to Jupiter. Weighing an impressive 3600 kilograms (8000 pounds) at launch, its Atlas V launch rocket couldn't fling it directly to the King of the Planets. Instead, it has to be sneaky: It took a long elliptical flight outwards, past the orbit of Mars, then came back to Earth to steal some of our energy. This is called a gravity assist, or more colloquially (if less accurately) a slingshot maneuver. On Oct. 9, 2013 it...