Origins of the ice giant model NASA’s Voyager 2 spacecraft flew past Uranus in 1986 and Neptune in 1989. These flybys remain the only close-up observations of either world. Voyager 2 measured each ...

Astronomers used a telescope in Hawaii to find a new object on the outer edges of our solar system, helping to fuel evidence of a long-standing theory about Planet Nine, or Planet X. For years, ...

Astronomers have spent years searching for a possible hidden giant planet far beyond Neptune. Unusual orbits among distant Kuiper Belt objects have fueled the Planet Nine theory, but recent ...

Diamond rain? Super-ionic water? These are just two proposals that planetary scientists have come up with for what lies beneath the thick, bluish, hydrogen-and-helium atmospheres of Uranus and Neptune ...

For more than a decade, astronomers have chased a planet that no one has ever seen. The case for a hidden ninth planet rests ...

Before the Voyager 2 flyby of Uranus and Neptune, these two distant planets were thought to be cold, dead worlds on the outskirts of the solar system. The historic spacecraft visit, however, revealed ...

When Voyager 2 flew by Uranus and Neptune 40 years ago, astronomers were surprised that it detected no global dipole magnetic fields, like Earth's. The explanation: the ice giants are layered and ...

Our solar system is our immediate cosmic neighborhood. We know it well: the sun at the center; then the rocky planets Mercury, Venus, Earth, and Mars; and then the asteroid belt; followed by the gas ...