HST took its first pix of Neptune in 2005.
Hubble has never "explored" Neptune. It is a telescope in orbit round Earth and from Earth it has "imaged" Neptune. It has done this several times eg 1996 and 1998 (there may be more times!).
The Hubble space Telescope
Voyager 2 flew past Neptune in August 1989. The HST took its first pix of Neptune in 2005.
2005
Neptune was discovered in 1846. Pluto was discovered in 1930 Hubble launched in 1990.
The Hubble Space Telescope was named after Edwin Hubble.
Voyager 2 is the only space craft that has studied Neptune, other than The Hubble Space Telescope
Hubble telescope The Hubble Space Telescope.
The Hubble Space Telescope.
The Hubble Space Telescope.
The Hubble telescope went into space in the cargo bay of the Space Shuttle.
No, it isn't. The Hubble Space Telescope is a reflector. It has a primary mirror, and not a primary lens.