Juno was launched in 2011, and won't make it to Jupiter until July of 2016. Since Jupiter is damn far from here (400 million miles or so), Juno has to take advantage of the Earth's gravity to slingshot it towards the outer solar system, which meant flying out past the orbit of Mars, careening back around Earth, and then (finally) heading out for the gas giants. This makes the total trip length just a smidge under 1.76 billion miles, and today is Juno's first and last close pass of home.
In the video below, Bill Nye does some explaining of how gravity assists work, in the way that only Bill Nye can.
Every day, DVICE selects fresh images, videos and more from the wonderful world of technology. See them all by clicking this link.