Which Planet is Your Fave?

[Digimon_Sommelier]

I was always fascinated by Pluto but now it's not a planet.

Will be again soon!!

[Clayton_n]

I like the 10th planet... or planetoid if you want to nit pick.



Eris (minor-planet designation 136199 Eris) is the most massive and second-largest (by volume) dwarf planet (and plutoid) known in the Solar System. Eris was discovered in January 2005 by a Palomar Observatory-based team led by Mike Brown, and its discovery was verified later that year. In September 2006 it was named after Eris, the Greek goddess of strife and discord. Eris is the ninth most massive object directly orbiting the Sun, and the sixteenth most massive overall, because seven moons are more massive than the known dwarf planets. It is also the largest which has not yet been visited by a spacecraft. Eris was measured to be 2,326 ± 12 kilometers (1,445.3 ± 7.5 mi) in diameter.[8] Eris's mass is about 0.27% of the Earth mass,[10][16] about 27% more than dwarf planet Pluto, although Pluto is slightly larger by volume.[17]

Eris is a trans-Neptunian object (TNO) and a member of a high-eccentricity population known as the scattered disk. It has one known moon, Dysnomia. As of February 2016, its distance from the Sun was 96.3 astronomical units (1.441×1010 km; 8.95×109 mi),[13] roughly three times that of Pluto. With the exception of some long-period comets, until 2018 VG18 was discovered on December 17, 2018, Eris and Dysnomia were the most distant known natural objects in the Solar System.[13]

Because Eris appeared to be larger than Pluto, NASA initially described it as the Solar System's tenth planet. This, along with the prospect of other objects of similar size being discovered in the future, motivated the International Astronomical Union (IAU) to define the term planet for the first time. Under the IAU definition approved on August 24, 2006, Eris is a "dwarf planet", along with objects such as Pluto, Ceres, Haumea and Makemake,[18] thereby reducing the number of known planets in the Solar System to eight, the same as before Pluto's discovery in 1930. Observations of a stellar occultation by Eris in 2010 showed that its diameter was 2,326 ± 12 kilometers (1,445.3 ± 7.5 mi), very slightly less than Pluto,[19][20] which was measured by New Horizons as 2,376.6 ± 3.6 kilometers (1,476.8 ± 2.2 mi) in July 2015.[21][22]