1 For thousands of year, we have been looking at the sky. We have studied other planets and tried to understand them. But to learn more about the planets in our solar system, we have to get closer to them. In September 1977, America sent Voyager 1 into space to get a closer look other planets. Voyager 1 has been travelling through space ever since and has flown past a number of planets in our solar system. Now, it is nearly 17 billion kilometers from the Earth!