Question 1

True or false: Eris has a moon named Dysnomia, after the Greek goddess of lawlessness.

Accepted Answer

True. Eris’s only known moon is Dysnomia, named for the daughter of Eris in Greek myth, meaning 'lawlessness'.

Question 2

True or false: Eris was originally nicknamed 'Xena' by its discoverers after the TV warrior princess.

Accepted Answer

True. Before official naming, the team called it 'Xena' (from Xena: Warrior Princess), and its moon was 'Gabrielle'.

Question 3

True or false: Eris is so far from the Sun that its surface is covered in frozen methane, not just ice.

Accepted Answer

True. Eris’s surface has methane ice, giving it a whitish appearance, and its extreme distance keeps it frozen.

Question 4

True or false: Eris is so massive that its gravity once pulled Pluto out of its original orbit.

Accepted Answer

False. Eris is massive but not large enough to gravitationally yank Pluto; their orbital resonances with Neptune explain the dynamics.

Question 5

True or false: Eris was discovered before Pluto was reclassified as a dwarf planet.

Accepted Answer

True. Eris was found in 2005, and its discovery sparked the IAU reclassification of Pluto in 2006.

Question 6

True or false: Eris is the only dwarf planet known to have rings like Saturn.

Accepted Answer

False. No rings have been detected around Eris; Haumea is the only dwarf planet with a known ring system.

Question 7

True or false: Eris orbits the Sun in the opposite direction of most planets in our solar system.

Accepted Answer

False. Eris has a highly tilted orbit but still orbits the Sun in the same prograde direction as the planets.

Question 8

True or false: Eris is larger than Pluto in both diameter and mass.

Accepted Answer

False. Eris is more massive than Pluto but slightly smaller in diameter; recent data shows Pluto is a bit wider.

Eris Trivia Questions