10th Planet Larger Than Pluto?
nova_planitia writes “The Minor Planet mailing list is buzzing with the discovery by an amateur astronomer of a 17th magnitude object 51 astronomical units from the Sun, tentatively designated 2003 EL61. For those not versed in astronomical lingo, this is an object several times brighter than Pluto even though it is 25% farther out from the Sun (the orbit vizualised by JPL). This means that barring a strangely reflective surface, this object is larger than Pluto, possibly Mars-sized! The debate whether Pluto is a planet is likely to get rekindled by this discovery.”
JCY2K writes “According to The Inquirer, hackers gained access to the secure server where the data about the new planet was being held and threatened to reveal it. Evidently the discoverers have been withholding this information from the public since 2003 while they waited for full analysis.”
Update: Bob Waters was so kind to send me a correction on this post: “Actually, the object larger than Pluto is 2003 UB313, discovered the next day, and also hailed as the tenth planet. Unlike 2003 UB 313, however, 2003 EL 61- which appears to have about a third of Pluto’s mass – has a moon.”
August 7th, 2005 at 02:49
Actually, the object larger than Pluto is 2003 UB313, discovered the next day, and also hailed as the tenth planet.
Unlike 2003 UB 313, however, 2003 EL 61- which appears to have about a third of Pluto’s mass- has a moon.
Don’t feel bad. I confused the information about the two on my blog for a week before I noticed that the news stories used two different designations for “the tenth planet,” and thought the information about 2003 EL 61 was later data about 2003 UB313!
My own proposal for a definition of “planet:” “Any solar system object with enough mass to be forced into a roughly spherical shape by its own gravity, and orbiting no primary other than the Sun.” Given the variation in size, physical characteristics, and orbit of the objects already recognized as planets, I think it’s the only definition that makes sense- and if it leads to a huge number of new “planets’ constantly being discovered, what are you gonna do?
August 10th, 2005 at 03:06
Hi Bob, Thank you for the info. I was just talking about this today, what defines a planet.. My conclusion was much like yours: “A massive object in steady orbit around a sun. Preferbly spherical, but my guess is that all big things in orbit will eventually become round, like rocks are polished round through time in the ocean.”