How many dwarf planets are there in our solar system? The recent discovery of 2017 OF201 makes the tally anywhere between ...

Over the past decade, researchers have been puzzling through Pluto’s mysteries. Meanwhile, the New Horizons probe heads for interstellar space.

Sedna will make its closest approach to the Sun in 2076, giving us a rare opportunity to visit the planetoid before it drifts ...

Scientists may have discovered a dwarf planet far beyond Neptune — an unearthing that may disprove a longstanding theory ...

Pluto was long considered our ninth planet, but the International Astronomical Union reclassified Pluto as a dwarf planet in ...

Among the roughly 10 billion white dwarf stars in the Milky Way galaxy, a greater number than previously expected could provide a stellar environment hospitable to life-supporting exoplanets ...

A dwarf planet called 50000 Quaoar that orbits beyond Neptune appears to have a ring that shouldn't be there, at 7.4 times more distant than the planet's radius.

A new dwarf planet named 2017 OF201 has been discovered far beyond Neptune. It sits in a region previously thought to be empty. Its existence raises questions about the structure of our solar ...

Almost 10 years ago, a NASA spacecraft was able to take several photos of Pluto, known for decades as a planet before it was reclassified as a dwarf planet in 2006.

A team of scientists at the Institute for Advanced Study School of Natural Sciences in Princeton, New Jersey, might have found a new dwarf planet, potentially leading to more evidence of a ...

The planets in order from the Sun are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. If you include the ...

Discovery of 2017OF201, a large trans-Neptune Object, challenges previous beliefs about the Kuiper Belt and hints at the existence of a theoretical Planet Nine.