January 5 , 2005 , is an galactic day of remembrance that is not really pronounced but should be . It see the discovery of midget planet Eris and how those very observation led to a novel way to describe the Solar System and herald the eventual alteration of Pluto ’s global status .
On that fateful January twenty-four hour period , the squad of Mike Brown , Chad Trujillo , and David Rabinowitz discoveredEris . The team had discover two objective in the years before – Sedna and Quaoar – moth-eaten , distant worlds , far beyond the reach of Neptune . At the time , some people speculated on whether they should be admit in the canonical listing of planet , but being smaller than Pluto , they were easy to brush aside as something else .
Not Eris . name after the Goddess of discord and strife , Eris was estimated , at the metre , to be larger than Pluto . That was theKill Billsiren announce the end of the Solar System ’s nine - major planet view as it had been for 70 eld . No longer would we sayMy Very Easy Method Just Speeds Up Naming Planets – there could not perhaps be nine planets any longer .
Alongside , Sedna , Quaoar , and Eris , there was also the discovery of Makemake and Haumea , which called for a better way to separate planet . There were multiple proposals on how to change it , though , in the end , the definition created a new class ofdwarf planetsand made a mickle of hoi polloi angry .
Still , kids in schooling now learn that the Solar System is not just the eight major planet but also at least five dwarf planets , hundreds of moons , one thousand thousand of asteroids and comets , and a good deal of other object we are yet to find .
Eris is more monumental than Pluto but has a pocket-sized volume . It has only one known Moon , shout out Dysnomia , and it orbits the Sun in just over 559 year . At its closest approach , Eris is 5.7 billion kilometer ( 3.5 billion sea mile ) from the Sun , about 38.3 clip further away than the Earth is from the Sun . Its next closest advance is give way to happen around December 2257 .
Last summer , a unexampled marriage proposal was put forth at theInternational Astronomical Union General Assemblyto deal a Modern definition of a major planet , establish on more clear , measurable terms . The current definition has several limitation and a pretty gross one is that it does n’t admit the over 5,000 confirmedexoplanetsthat we have learn in the creation .
The scientist that proposed it hope that thenew definitionwill be discussed at the next General Assembly in Rome in 2027 . It command that a major planet orbits a star or a brown midget – a lunation can not be a satellite – and that it has a mickle higher than 1023kilograms ( 2.2 x 1023pounds ) . No prize for infer that Pluto and Eris are too light to pass that threshold .
Eris has the most liable name ever given to a celestial body . No matter the side of the planetary debate you are on , nobody has been happy about the definition of the planet since this world was discovered . So , happy discovery day Eris , and All Hail Discordia !
