HUBBLE FINDS 'TENTH PLANET' IS SLIGHTLY LARGER THAN PLUTO

Under what qualifications are Xena, Sedna and Quaoar (what a name!) not planets given that pluto is ?

Under what qualifications are Xena, Sedna and Quaoar (what a name!) not planets given that pluto is ?

Becasue the IAU havn't said they are. ATM the definition of a planet is "if we say it's one it's one, otherwise it isn't"

Dont you just love the scientific thinking behind that mentality. :lol:

An even bigger problem they have is properly designating extra solar planets in a manner that relates them to their parent star. apparently at the moment its some non descript catalogue number

I've just read somewhere too that Xena is the second brightest object in the Solar System after Saturns moon, Enceladus. It must be covered in clean, primordial ice all over - this could be its first trip this close to the Sun.

I've just read somewhere too that Xena is the second brightest object in the Solar System after Saturns moon, Enceladus. It must be covered in clean, primordial ice all over - this could be its first trip this close to the Sun.

From Terrys email last night perhaps?

5. SMALL BUT SHINY XENA.
The outer Solar System continues to surprise and amaze! On top of all the incredible pictures of Saturn's moons from Cassini, it has now been found that 'Planet X', officially still called 2003 UB313, but generally dubbed as Xena, is almost the most reflective object in the Solar System - second only to Enceladus. It lies about three times as far from the Sun as Pluto, and its brightness suggested it was considerably larger than Pluto. But discoverer Mike Brown and colleagues have analysed Hubble images taken in December 2005 to reveal Xena's size as 2400 kilometres (+/- 100) - only about 5% larger than Pluto’s 2290 kilometres. Xena's brightness, yet small size, means that it must reflect about 86% of the sunlight falling on it. Spectra suggest its surface is covered with methane.