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).

A fifth planet has been detected within the habitable zone of a neighboring star, where conditions could perhaps support ...

In August 2006 the International Astronomical Union General Assembly adopted a resolution to reclassify Pluto as a dwarf planet. The reasoning was that it didn't satisfy one of three newly defined ...

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.

U.S. astronomers hunting for "Planet Nine" have instead stumbled on what appears to be a new dwarf planet in the solar system's outer reaches.

A dwarf planet is classified as a celestial body that orbits the sun that has enough mass and gravity to be mostly round, but unlike other planets, has not cleared its orbital path of asteroids ...

Potential discovery of new dwarf planet adds wrinkle to Planet Nine theory By Nick Butler, Fox News Published May 31, 2025, 6:00 a.m. ET ...

A newly discovered dwarf planet called 'Ammonite' (2023 KQ14) has been spotted in the outer solar system, and it could be another nail in the coffin for the Planet Nine hypothesis.

But a Planet Nine would nudge the closest part of 2017 OF201’s trajectory inward until Neptune flung it out of the solar system. That would happen pretty quickly, within about 100 million years.

Scientists at the Institute for Advanced Study in Princeton, New Jersey, discover a new trans-Neptune Object, 2017OF201, potentially discrediting 2016 theory of Planet Nine.

WASHINGTON (Reuters) -Scientists have identified an object about 435 miles (700 km) wide inhabiting the frigid outer reaches of our solar system that might qualify as a dwarf planet, spotting it ...