Eris’ moon has also been given a name – Dysnomia. In mythology, Dysnomia was the daughter of Eris and was known as the spirit of lawlessness. I love the appropriateness of both names.

Our dwarf planet (the largest discovered so far) now has a name! It has been named Eris. The name, Eris, comes from the Greek goddess of chaos and strife, which is an appropriate name, since our dwarf planet caused so much havoc in the astronomical community. In mythology, Eris caused a quarrel among goddesses that [...]

According to Space Daily, the IAU definitions of objects in our solar system can be best described this way: The International Astronomical Union has decided that, to be called a planet, an object must have three traits. It must orbit the sun, be massive enough that its own gravity pulls it into a nearly round [...]

The IAU decided today that our beloved tenth planet will not be defined as a planet. In fact, Pluto has been stripped of its planetary title as well. It’s a sad day here.

The IAU is proposing the following definition of a planet, which would make our beloved tenth planet, really the 12th planet! A planet is a celestial body that (a) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (b) is in orbit [...]

The IAU (International Astronomical Union) will propose a definiton of a planet on August 18, 2006, and a vote on that proposed definiton will take place on August 24, 2006. Such a definition holds the fate of the tenth planet, as well as possibly the fate of Pluto. Are either of them a planet? One, [...]

For the first time, NASA’s Hubble Space Telescope has seen distinctly the “tenth planet,” currently nicknamed “Xena,” and found that it’s only slightly larger than Pluto. Though previous ground-based observations suggested that Xena’s diameter was about 30 percent greater than Pluto, Hubble observations taken Dec. 9 and 10, 2005, showed Xena’s diameter as 1,490 miles [...]

A group of amateur astronomers has used the 2.1-meter (82-inch) Otto Struve Telescope at McDonald Observatory to make the first ‘through-the-eyepiece’ sighting of so-called the tenth planet, an object orbiting the Sun in the Kuiper Belt, far beyond Pluto. The group includes members of the St. Louis and Rockland Astronomical Societies, and a few others. [...]

Although the IAU determined in late 2005 that an object can be considered a planet if it is at least the size of Pluto, it decided to ask the Division of Planetary Sciences (DPS) of the American Astronomical Society for its recommendation as well. The IAU will be meeting in Prague in August, 2006, where [...]

The University of Bonn, using a 30-meter IRAM telescope, have determined that 2003 UB313 has a diameter of 3000 +/- 400 km. Like Spitzer, IRAM measures the heat given off from the object, but IRAM is a much larger telescope than Spitzer. Due to its size, it was able to measure the heat output in [...]