This is an artist's impression of the gas-giant planet orbiting the yellow, Sun-like star HD 209458, 150 light-years from Earth.
The pick for 2001 shows the more groundbreaking aspects of which Hubble is capable. This planet may look like Jupiter, but it is actually a exoplanet orbiting a star in another solar system. Both star and planet are located in the Pegasus constellation, and prove that it is entirely possible for the HST to observe the chemical make-up of planets well beyond our solar system.