Eris
Where is Eris?
Look south, about 39° up at 01:56 in Cetus.
- Rises
- 19:48
- Highest
- 01:51
- Sets
- 07:54
- Best after dark
- 01:56 · 39°
Can I see Eris tonight?
From London tonight, Eris is above the horizon after dark. It’s highest after dark at 01:56, in the south at 39°.
At magnitude 18.6 it needs a large telescope, a dark sky and a detailed chart.
This is position and timing only: clouds, haze and light pollution aren’t included.
What does Eris look like?
Eyes
Not visible.
Binoculars
Not visible.
Telescope
Beyond amateur telescopes. Only large instruments with cameras record it.
About Eris
Eris is one of the most distant known members of the Solar System. It is almost exactly the size of Pluto but about a quarter more massive, and it is currently close to the farthest point of its orbit, nearly three times farther from the Sun than Pluto.
Its discovery in 2005 started the debate that led the International Astronomical Union to define the word “planet” in 2006. Eris, Pluto and Ceres became the first dwarf planets.
Eris is named after the Greek goddess of strife and discord, fitting for the argument it caused. Its moon, Dysnomia, is named after her daughter, the spirit of lawlessness.
At around magnitude 18.7, Eris is far beyond the reach of backyard telescopes.
Eris’s orbit is steeply tilted, about 44° to the plane of the planets, and very stretched: its distance from the Sun ranges from roughly 38 to 98 times Earth’s. Its surface is brilliant, probably coated with frozen methane, and reflects almost as much light as fresh snow. A team led by Mike Brown found it in images taken in 2003.
Other dwarf planets
Questions
Is Eris bigger than Pluto?
Why did Eris change the definition of a planet?
How long is a year on Eris?
Sources: SkyMate; IAU Minor Planet Center; star chart: Wikidata (CC0). Positions computed for your place and time with astronomy-engine. Data & Licences