"It was obvious within the first ten seconds that this changed everything." Mike Brown, an astronomer in Caltech's Palomar Observatory, had just discovered an unknown object nearly as big as Pluto far out in the solar system's Kuiper Belt. It would come to be known as Eris. Its discovery in 2005 rocked the world of astronomy and forever changed what elementary school students would be taught about the solar system.

The detection of Eris, and of other large objects in the Kuiper Belt, eventually led to the classification of a new type of space object, a dwarf planet. And to much public outcry, it also led to the downgrading of Pluto from planet to dwarf-planet status.

Wednesday, Oct. 2, at 1 pm PST/ 4 pm EST was live chat with astronomer Mike Brown and science writer Brad Hooker, they explored this monumental discovery and what dwarf planets mean to science today. Read the complete archive of this Q&A below

Be sure to read Brad Hooker's fascinating background story on MemberCentral, "From Discovery to Demotion: How a Dwarf Planet Changed Astronomy." And watch an interview by Science NetLinks with Mike Brown and how he feels about the Pluto debate.

Michael Brown is currently the Richard and Barbara Rosenberg Professor of Planetary Astronomy at the California Institute of Technology. He specializes in the discovery and study of bodies at the edge of the solar system. Among Brown's numerous scientific accomplishments, he is best known for his discovery of Eris, the largest object found in the

solar system in 150 years, and the object which led to the debate and eventual demotion of Pluto from a real planet to a dwarf planet. Brown is the author of "How I Killed Pluto and Why It Had It Coming," a bestselling memoir of the discoveries leading to the demotion of Pluto.

Brad Hooker is a freelance writer specializing in science and the environment. In addition to covering physics and astronomy for MemberCentral, his recent publications include a personal narrative on the F-14 Tomcat for Air & Space Smithsonian, an adventure travel piece for The Oregonian and a Q&A with the science advisor behind the CBS show "The Big Bang Theory" for Symmetry Magazine. He is also a senior writer at the University of California, Davis, where he covers the latest research from plant scientists who are tackling critical issues related to feeding the planet.