Eris size and scale context

Eris is a distant dwarf planet in the scattered disk beyond Neptune. Its discovery helped trigger the 2006 planet-definition debate, and its tiny moon Dysnomia lets astronomers measure its mass. Read its scale context, comparisons, and journey links on the canonical object page.

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Between the smallest and the largest, perspective is everything.

About

Scale of Space is a scroll-based journey through the universe, placing objects on a single logarithmic scale so you can compare size across an unbroken range.

Guides turn parts of that scale into curated essays, while focused views let you explore the same range through specific groups of objects.

Editorial

Solar System Planets From Electron to Atoms Stars To Scale Birth And Death Of Stars Black Holes To Scale

Views

Planets of the Solar System Stars of the Universe Black holes Subatomic scale

Return to Earth hello@scaleofspace.org

Between the smallest and the largest, perspective is everything.

About

Scale of Space is a scroll-based journey through the universe, placing objects on a single logarithmic scale so you can compare size across an unbroken range.

Guides turn parts of that scale into curated essays, while focused views let you explore the same range through specific groups of objects.

Editorial

Solar System Planets From Electron to Atoms Stars To Scale Birth And Death Of Stars Black Holes To Scale

Views

Planets of the Solar System Stars of the Universe Black holes Subatomic scale

Return to Earth hello@scaleofspace.org

Dwarf planets

Ceres

Ceres is the largest object in the asteroid belt and the smallest recognized dwarf planet. NASA’s Dawn mission showed that its brightest spots are salt deposits left by briny water rising from below, revealing Ceres as a surprisingly active water-rich world.

Scale fact940 kmmean diameter

Object class: Dwarf planet
Mass: ~0.00016 Earth masses
Host: Sun
Estimated age: ~4.56 billion years
Composition: Rock and water ice
Temperature: ~167 K mean surface

Dwarf planets

Eris

Eris is a distant dwarf planet in the scattered disk beyond Neptune. Its discovery helped trigger the 2006 planet-definition debate, and its tiny moon Dysnomia lets astronomers measure its mass.

Scale fact2,326 kmmean diameter

Object class: Dwarf planet
Mass: ~0.0028 Earth masses
Host: Sun
Estimated age: ~4.5 billion years
Composition: Rock and ice

Dwarf planets

Pluto

Pluto is an icy dwarf planet with a surprisingly active surface and atmosphere. New Horizons found nitrogen-ice glaciers flowing across its plains and blue hazes in its sky, showing that even the Kuiper Belt can host dynamic worlds.

Scale fact2,380 kmdiameter

Object class: Dwarf planet
Mass: ~0.0022 Earth masses
Host: Sun
Estimated age: ~4.5 billion years
Composition: Rock, water ice, nitrogen and methane ices
Temperature: ~44 K mean surface