/r/eris

Photograph via //r/eris

Articles and discussion about dwarf planet Eris.

Eris is a dwarf planet orbiting the sun, in the Scattered Disc beyond Neptune. It is best known as the body whose discovery ultimately resulted in the 'demotion' of Pluto from planetary status.


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7

I don't think Dwarf Planet Eris has a surface as bland as people claim (with help from Dysnomia)

Eris has been claimed to have a bland surface, since it's a uniform pale white. Even though I'm an amateur astronomer, I disagree and would like to challenge this statement.

First of all, Rotation. Eris rotates every 16 days, facing its moon Dysnomia in a double tidal lock. It had been assumed to be 26 hours in the past, which is barely over a 1/16th. Putting that into math using surface area equations, it means we've only seen 57% of the surface in a single observation of a 7% change. That's about 1.7 hours essentially of earth for comparison. Way more of Eris unseen could have more dynamic features. This doesn't take into account its 60° tilt (30% is in nonstop sunlight) or any recent observations, but NASA's page still lists 26 hours as its rotation. This is still disputable though, so correct me if I'm wrong. Dysnomia has helped us find out this, but it's already been known to be tidally locked. Still could be interesting though as it's larger than Miranda and Enceladus.

Second, Sputnik Planets. Eris and Makemake are theorized to be them, Global versions of Pluto's Sputnik Planita. Gigantic convection cells, dozens if not maybe even hundreds of kilometers across, could dot the surface. That alone is the opposite of bland to me, as it means it has one of the most active geological surfaces in the solar system. Not as much as Earth, Io, Europa, Enceladus, or potentially Triton, but still very dynamic. Thanks to A. Ramirez & M. Hernandez for the artwork above at UCF, showcasing these cells.

What do you guys think about this?

2 Comments
2024/04/14
00:51 UTC

9

Eris's moon Dysnomia: the furthest moon from the Sun (and also the moon that killed Pluto)

0 Comments
2017/06/06
15:20 UTC

16

The size of Eris (left) compared to the Moon and the Earth • image courtesy of space-facts.com

0 Comments
2016/12/22
21:09 UTC

8

Demonstration of how Eris' size was approximated, using star occultation from several locations

1 Comment
2016/12/22
20:16 UTC

16

Eris orbit compared to the outer Solar System

2 Comments
2016/08/05
17:14 UTC

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