The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

The building blocks of life could have been delivered to solar system dwarf planet Ceres by one or more space rocks from the outer asteroid belt.

Among the roughly 10 billion white dwarf stars in the Milky Way galaxy, a greater number than previously expected could ...

Gaia-4b is considered a super-Jupiter planet, a relatively cold gas giant, orbiting its star over 570 Earth-days. That star ...

Enceladus, a moon of Saturn, and Europa and Ganymede, moons of Jupiter, are all thought to have saltwater oceans buried under icy shells. Dwarf planets Pluto and Ceres are also suspected of having ...

In 2006, the International Astronomical Union (IAU) voted on the definition of a planet. Famously, Pluto no longer met the ...