Ceres is a gas planet.
Ceres ( [ ˈsɪəriːz ] minor-planet designation : 1 Ceres ) is the largest object in the asteroid belt that lies between the orbits of Mars and Jupiter . It was originally considered a planet , but was reclassified as an asteroid in the 1850s after many other objects in similar orbits were discovered . A gas dwarf is a gas planet with a rocky core that has accumulated a thick envelope of hydrogen , helium , and other volatiles , having as result a total radius between 1.7 and 3.9 Earth radii .