A recently discovered celestial body is rewriting our knowledge of the Kuiper Belt and maybe challenging the existence of the ...

It had not been thought possible that such tiny, weak stars could provide the conditions needed to form and host huge planets.

Still, Ceres remains a dwarf planet. Perhaps as it should, given Pluto's relegation to dwarf planet — Pluto is 14 times larger than Ceres. Both Ceres and Pluto are given this designation because ...

when the spunky world Pluto was demoted from a planet to a dwarf planet. Now, a team of astronomers is pushing for “planet” itself to be redefined to encompass bodies that orbit stars besides ...

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 ...

When the International Astronomical Union (IAU) demoted Pluto from a planet to a dwarf planet in 2006, it surprised a lot of people, including some scientists. Even many years later, some ...

In this region, objects in space could cross any dwarf planet — and Pluto’s — orbit. Pluto also sits within a larger field of objects surrounding the solar system called the Kuiper Belt.

Arizona in 1930 and was considered our ninth planet until 2006. The International Astronomical Union reclassified Pluto as a dwarf planet because it does not clear its orbit of other debris.

IAU members decided that there were three criteria to be a planet — and Pluto didn't meet all of them. But planetary scientist Wladymir Lyra says that even though it was downgraded to a dwarf ...

Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute When the International Astronomical Union (IAU) demoted Pluto from a planet to a dwarf planet in 2006 ...