When astronomers found a large world farther out than Pluto, it became one of the final nails in the coffin of our ninth ...

Dwarf planet Pluto ... They emerge from the farthest reaches of the solar system, way beyond the orbit of Neptune, then zip past the sun before disappearing again for centuries.

Astronomers have discovered an exoplanet that might have favorable conditions for liquid water. This planet, HD 20794 d, ...

Astronomers discovered the exoplanet in 2016, a gas giant that’s slightly larger than Jupiter with a fraction of its mass, ...

It is located in a star system less than 20 light-years away, making it one of the closest candidates for further research.

Just as the Winter Solstice marks the point in the tilting of Earth's axis at which it points the farthest from the sun, the Summer Solstice marks the point at which our planet has its maximum ...

The dwarf planet is a bizarre, cryovolcanic world. However, the organic deposits discovered on its surface so far are unlikely to originate from its interior. The organic material found in a few areas ...

The organic material found in a few areas on the surface of dwarf planet Ceres is probably of exogenic origin. Impacting ...

The two planets are farthest apart when they are both at their farthest from the sun, on opposite sides of the star. At this point, they can be 250 million miles (401 million km) apart.