How many dwarf planets are there in our solar system? The recent discovery of 2017 OF201 makes the tally anywhere between five and 18, plus hundreds of potentially undiscovered ones, depending on ...

But things changed nearly five years ago today. On Aug. 24, 2006, the International Astronomical Union (IAU) struck Pluto from the list, demoting it to the newly created category of " dwarf planet ." ...

Its size is estimated to be a bit smaller than Ceres, which is the smallest of the solar system's five recognised dwarf planets and has a diameter of about 590 miles (950km).

Pluto, the largest of those dwarf planets, has a diameter of about 1,477 miles (2,377 km). The mass of 2017 OF201 is estimated to be about 20,000 times smaller than Earth's and 50 times smaller ...

Astronomers have discovered a new world circling the outer edges of our solar system. So far, there are only four known ...

Pluto, the largest of those dwarf planets, has a diameter of about 1,477 miles (2,377 km). The mass of 2017 OF201 is estimated to be about 20,000 times smaller than Earth’s and 50 times smaller ...

A possible dwarf planet, like Pluto, has been observed in our solar system, according to a preprint published in arXiv. The area of space where this planet was found was previously thought empty.

The dwarf planet Eris is one of the most reflective objects in our solar system, astronomers say in a study uncovering a trove of information about the mysterious object beyond Pluto.

Its size is estimated to be a bit smaller than Ceres, which is the smallest of the solar system's five recognized dwarf planets and has a diameter of about 590 miles (950 km). Pluto, the largest of ...