Voyager 1 Will Say Goodbye, Forever
Starting in 2005, Voyager 1 started to make some exciting phone calls home. Launched all the way back in 1977, the plucky little probe told its friends on Earth that it was picking up cosmic rays and other strange forces, indicating it had entered the Termination Shock (in other words, the beginning of the end of the solar system). Since then it has been traveling in the Heliosheath, still under the influence of the Sun but steadily traveling towards interstellar space. Scientists estimate it will set on the great uncharted ocean of deep space between 2013 and 2015, but we're putting our money on this year (because why not?). Voyager 1 will be the first spacecraft to ever journey beyond the solar system. Bon voyage, old friend!