Dysnomia is a small moon of dwarf planet Eris, notable for its role in helping scientists understand the characteristics of Eris and its orbital dynamics. Its observations contribute valuable data about the outer Solar System and the formation of icy dwarf planets and their moons.

1. 1. Physical Characteristics

• • • Diameter: Dysnomia has an estimated diameter of about 700 km (435 miles). This size makes it relatively small compared to many other moons in the Solar System.
    • Mass: Its mass is not well-determined but is estimated to be significantly less than that of larger moons.
    • Density: The density is not precisely known, but it is assumed to be like that of other small icy moons, composed primarily of water ice and rock.

 

1. 2. Surface Features

Little detailed information is available about Dysnomia’s surface composition. It is likely covered with a mix of water ice and other frozen volatiles, like other small moons in the outer Solar System.

 

1. 3. Orbit

• • • Orbit around Eris: Dysnomia orbits Eris at an average distance of about 37,000 km (23,000 miles). Its orbital period is approximately 16 Earth days.
    • Synchronous Rotation: Dysnomia is thought to be tidally locked with Eris, meaning the same side always faces the dwarf planet.

 

1. 4. Temperature

As with other bodies in the outer Solar System, Dysnomia’s surface temperatures are extremely cold, averaging around -240°C (-400°F).

 

1. 5. Exploration

Dysnomia has been observed only indirectly through telescopic imaging and measurements of Eris. Its discovery was announced in 2005, and detailed observations have been limited to those made from Earth-based telescopes.

 

1. 6. Scientific Significance

• • • Understanding Eris: Studying Dysnomia helps scientists understand more about Eris’s mass and density, as Dysnomia’s gravitational influence provides insights into the characteristics of its parent body.
    • Moon Formation: The presence and characteristics of Dysnomia offer clues about the formation and evolutionary processes of Eris and other similar distant icy bodies.

 

1. 7. Interesting Facts

Dysnomia is named after the daughter of Eris in Greek mythology. Eris is the goddess of discord, and Dysnomia represents lawlessness or anarchy.