|This is the best photo of the planet Pluto we have untill now. At least until NASA's new horizon mission arrives to Pluto in July 2015.|
Pluto was the most distant planet in our solar system, until astronomers discoverd new Kuiper belt objects. Officially Pluto lost the "title" of a planet and now is considered as a dwarf planet (and generally is a Kuiper belt object).
We practically know nothing about Pluto. We know it has one big moon (for its size) which is called Charon (it's the small spot you see on the top right of the photo) and four smaller ones (Nix, Hydra,Kerberos and Styx). This particular photo was taken by the space telescope Hubble at 21 February of 1994, when the distance of the planet from Earth was 4,4 billion km. The photo is very clear in comparison to those surface telescopes and we can see the two objects perfectly separated
From this photo astronomers managed to measure both the dimensions of Pluto and Charon more accurately. Pluto's diameter is about 2320 Km and Charon's about 1270 Km. Due to the fact that Charon has large dimensions it doesn't orbit around the centre of Pluto (as it happening with the Earth - Moon system). Both objects are orbiting around their common mass center, which is many kilometers above Pluto's surface (but closer to it). It can be observed by the photo that Pluto and Charon have a different surface composition and structure, since Pluto seems to reflect more sun light than the Charon. This means that Pluto has a flatter surface, which is constituted from a layer of a high reflection material (possibly ice).
Using Hubble images astronomers where able to create a computer-generated map of Pluto
Moreover we can clearly see bright and dark spots. We can also see that Pluto has a light pink color.
Note: The images were taken from NASA and wikipedia