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.
Facts about Neptune. 1  It takes Neptune 164.8 Earth years to orbit the Sun. 2  Neptune was discovered by Jean Joseph Le Verrier. 3  Neptune is the Roman God of the Sea. 4  Neptune has the second largest gravity of any planet in the solar system â second only to Jupiter. 5  The orbit path of Neptune is approximately 30 astronomical units (AU) from the Sun.