Swapping Neptune and Uranus could help explain solar system's formation.
Uranus is the seventh planet from the sun and the third-largest planet in the solar system. The blue-green gas giant has the coldest atmosphere of all the planets in the solar system. Uranus is the only planet in the solar system that orbits the sun on its side, and this extreme tilt is responsible for turning the planet's magnetic fields into a jumbled mess. So far only NASA's Voyager 2 spacecraft has studied the planet up close during a flyby in 1986, but researchers are still studying the planet with telescopes on and around Earth.
Images of Uranus taken in August by the Hubble Space Telescope (HST) show that a dark spot has formed in the planet’s northern hemisphere.
The shadow cast by a moon as it floated through space above the blue-green cloud tops of Uranus was recently captured for the first time by NASA's Hubble Space Telescope.
Astronomers have discovered new rings and small moons around Uranus and found surprising changes in satellite orbits around the giant planet.