Neptune is a really big planet that is super far away from us, much farther than you can imagine. People have been interested in exploring Neptune for a very long time.
To explore Neptune, we send special machines called spacecraft. These are kind of like robots that we send into space to explore other planets. All the way back in 1989, NASA sent a spacecraft called Voyager 2 to visit Neptune. Voyager 2 used a special camera to take pictures of Neptune and sent them back to Earth. Scientists were able to study these pictures to learn more about Neptune and its moons.
But there's still a lot we don't know about Neptune, so scientists want to explore it even more. They're working on new ways to send spacecraft to Neptune so we can learn more about its atmosphere, its magnetic field, and the other things that make it unique.
Exploring Neptune is a big challenge because it's so far away, but scientists are very smart and they're always coming up with new ideas to find out more about this fascinating planet.