In the early hours of July 14, a NASA spacecraft will make a historic first encounter with Pluto, the beloved dwarf planet that currently sits about 2.9 billion miles from Earth. The New Horizons spacecraft will take the first close-range photos and scientific readings of the Pluto system, helping to clear up many mysteries of the dark, icy world and its strange flock of moons.

New Horizons won't orbit or land on Pluto, but will instead fly past and continue studying objects in a zone known as the Kuiper Belt—a vast area filled with the frozen remnants of the solar system’s building blocks. While that may seem like a brief visit, many space agencies and scientists know that a flyby can confirm truths and reveal hidden wonders about the planets and other objects that make up our celestial neighborhood.

Here are just a few of the accomplishments of the first probes to visit the other members of the solar system's planetary family: