If you've opened a fortune cookie, you've probably read an aphorism, like this one, 'The world may be your oyster, but that doesn't mean you'll get its pearl.' In just a few words this quote tells the reader a lesson about life, that you have nearly limitless possibilities, but not all of them lead to a great reward.
The exploration of Neptune has only begun with one spacecraft, Voyager 2 in 1989. Currently there are no approved future missions to visit the Neptunian system. NASA, ESA and also independent academic groups have proposed future scientific missions to visit Neptune.
View full size image. New Horizons is a NASA spacecraft on its way to the dwarf planet Pluto. It scooted by Jupiter in 2007, and will pass by Pluto in July 2015 before possibly heading farther into the Kuiper Belt â a massive zone of icy bodies beyond Neptune.