It is a dwarf planet. 136199 Eris is just a large trans-Neptunian object like 136108 Haumea, 50000 Quaoar, 134340 Pluto, 136472 Makemake, 225088 (2007 OR10), 90482 Orcus and 90377 Sedna.
it is mostly made up of rock
Eris is solid.
Eris is composed mainly of ice and rock, similar to Pluto and other dwarf planets in the outer solar system. It is thought to have a rocky core surrounded by a thick layer of frozen water, methane, and nitrogen. Additionally, Eris is also believed to have a thin atmosphere consisting of methane gas.
The dwarf planet Eris is most probably a rocky planet with a surface covered in methane ice. There is currently no more accurate information on this object.
Eris's moon Dysnomia, appears to be made of material similar to Eris and Eris appears almost grey.
Eris is made of rock and ice.
Eris is made mostly of ice.
it is mostly made up of rock
There made of Rock and something else
hard as a rock because it is made of rock.
Eris is solid.
no
Eris is composed mainly of ice and rock, similar to Pluto and other dwarf planets in the outer solar system. It is thought to have a rocky core surrounded by a thick layer of frozen water, methane, and nitrogen. Additionally, Eris is also believed to have a thin atmosphere consisting of methane gas.
rock not gas
Rock.
gas
It is gas