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

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

Pluto isn't alone—it's part of the Kuiper Belt with possibly hundreds of other planet-sized objects. Because Pluto hasn't ...

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 ...

is a disc-shaped region beyond the orbit of Neptune’s in the outer solar system—50 Earth-sun distances—that’s home to dwarf planets like Pluto, Makemake and Eris. It’s also thought to be ...

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

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.

Feb. 15, 2024 — A team found evidence for hydrothermal or metamorphic activity within the icy dwarf planets Eris and Makemake, located in the Kuiper Belt. Methane detected on their surfaces has ...

In 2005, Eris was discovered. It was considered the largest known dwarf planet in the solar system until a year later when Pluto was downgraded from being a planet. In 2008, tribal violence following ...