The Sun
2003 UB313
Tenth Planet in our solar system discovered ( 2003 UB313 )
The planet's temporary name is 2003 UB313, but it makes you wonder what they are going to call the tenth planet in our solar system. Also referred to as a K.B.O ( Kuiper Belt Object ), like Pluto, this planet has an orbit outside that of Neptune at a range of approximately 97AU (astronomical units where 1AU is the distance from the earth to the sun).

2003 UB313 is larger than Pluto, and has a diameter of ~2500km making it about one and a half times the size of Pluto. 2003 UB313 is made of ice and rock, and it is the largest of the 432 KBOs that have been discovered to date. This latest discovery has sparked interest and further study of the regions beyond Neptune in hopes to improve our knowledge of our own solar system.

Exposure to cosmic rays over time darkens the surface of these objects and makes them hard to see against the night sky, but scientist are finding them at an alarming rate. New discoveries in this region of space is becoming a small but significant gold rush of the 21st century! All 432 KBO discoveries have come within a very short period of our history, and we've been photographing them for even longer. Scientist have gone back in the archives and pulled photos of these distant objects and are now recognizing them for what they really are.

It is estimated that there are over 70,000 KBOs in existence, so that leaves a rather large pool of discovery left for us, but don't expect to be able to see one of these with a back-yard telescope. It takes special techniques, and special instruments to bring these dark objects to light.

The discovery of the latest addition to our solar system is credited to Brown and colleagues using the Samuel Oschin Telescope at Palomar Observatory near San Diego.

Discuss Names in our Forum

Michael E. Brown (Discoverer of 2003 UB313) has a website -
2003 UB313 has a website -
Scientific Discovery Paper submitted to the IAU -

Home Page |  Webmasters |  Under 13 Terms |  About Us |  Contact Us
All material contained in this website, in whole or in part, is the property of
All rights are reserved, and you may not put it to use without the expressed consent of the administrator
Sign up for PayPal and start accepting credit card payments instantly.