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Object profile · MIRANDA

Miranda

Small fractured major moon of Uranus

The smallest major Uranian moon, where giant cliffs, grooves and oval coronae divide terrain of different ages.

Atlas data reviewed
Editorial stage
Published
Visibility
Public
Voyager 2 color composite of Miranda showing bright and dark banded terrain, craters, ridges and valleys.Direct observation
Voyager 2's best color view of Miranda, assembled from green, violet and ultraviolet filter images.

Official color composite from multiple filters. Only the imaged southern hemisphere is represented, and color is processed rather than an unaided-eye view.

NASA/JPL ↗
Vastward explanation

What this world is

Miranda looks divided into sharply different geological neighborhoods. The large oval regions of ridges and grooves are called coronae, but their origin is still debated.

Why it looks this way now

Voyager 2 directly imaged cliffs, fault valleys, craters and three coronae on the southern hemisphere. Heating, impact and resurfacing ideas compete, and no present ocean has been detected.

02

Where it sits

The innermost of Uranus' five major moons, orbiting just beyond the small inner moons and rings.

How to read this mapTwo-scale location · Solar System to the Uranus moons

Swipe sideways to inspect the full map

Two-scale location · Solar System to the Uranus moonsThe left panel places Uranus in planetary order; the right places Miranda among the profiled Uranus moon orbits.Scale one · Solar SystemUranusPlanet 7 from the SunSunScale two · Uranus moon systemUranusMirandaProfiled orbit 1 of 5Mean distance · 129,846 km
Blue marks the current moon and orbit

Miranda is 1 of 5 profiled Uranus moons by distance, at a mean center distance of about 129,846 km.

Muted lines and dots show system context

The left panel locates Uranus, dashed lines mark the scale change, and muted orbits and dots represent other profiled moons on the right. This is the innermost profiled moon in the system; Ariel is adjacent outside.

The figure uses two linked scales and compares only the same-system moons currently profiled by Vastward; orbit spacing, body sizes and marker positions are compressed for teaching.
03

Read the numbers

Reference values retain their units, context, evidence state and published uncertainty.

Physical measurements

Mean radiusglobal mean
235.8kmCalculated measurementThe mean radius is about 0.136 times the radius of Earth's Moon.

Irregular moons have no single true radius; the mean radius is an equal-volume comparison.

Published uncertainty: ± 0.7 km

JPL tabulated uncertainty for the adopted mean radius.

Massglobal mean
6.442623E19kgCalculated measurementMass is not read from a scale. Motion under gravity constrains GM, from which mass is derived.

Calculated from JPL GM with a conventional gravitational constant, then rounded for display.

Approximate value

Derived from JPL's gravitational parameter GM and a conventional gravitational constant, then rounded.

Mean densityglobal mean
1.1780g/cm³Calculated measurementThe lowest density of the five major Uranian moons, consistent with an ice-rich rock mixture.

This is a whole-body average and cannot by itself prove the composition of every interior layer.

Published uncertainty: ± 0.053 g/cm³

JPL tabulated uncertainty for the adopted mean density.

Reference gravitysurface
0.07734m/s²Calculated measurementRepresentative surface gravity is about 0.79% of Earth's.

Shape, terrain and local mass distribution make real gravity vary by location.

Approximate value

Calculated from the adopted GM and mean radius. Irregular shape and local terrain can change the actual value.

Temperaturesurface
-188°CScientific modelThis is an approximate sunlit upper reference, not a whole-moon average.

Sunlit terrain near the 1986 encounter could approach this value, while decades-long polar darkness can be much colder.

Approximate value

Approximate sunlit upper reference near 85 K during the Voyager-era geometry. It is not a global mean, and long polar night can be far colder.

Orbit and rotation

Average distancesystem reference
129,846kmCalculated measurementThis is a representative center-to-center distance between Miranda and Uranus.

The real distance changes around an elliptical orbit.

Approximate value

Rounded orbital distance from the moon center to the planet center. The real orbit is not a perfect circle.

Rotation periodrelative to distant stars
1.413479Earth daysCalculated measurementTidal locking makes one rotation take nearly the same time as one orbit around the planet.

This is a sidereal rotation, not a local sunrise-to-sunrise solar day.

Approximate value

Rounded synchronous rotation period. The same hemisphere normally faces the primary planet.

Orbital periodrelative to distant stars
1.413479Earth daysCalculated measurementThis reports the time for one orbit, not a claim that the path is perfectly circular.

A rounded sidereal period is used for the beginner-facing display.

Approximate value

Rounded sidereal orbital period.

04

Atmosphere and inside

Atmosphere

Miranda has no persistent atmosphere. Its weak gravity cannot retain released gas for long.

Surface and interior

Miranda is probably an ice-rich rock mixture below a fractured crust. A 2023 thermal model does not retain a present ocean in such a small body.

  1. 1
    Modeled rock-ice interior

    Density supports an ice-rich mixture with rock, but does not reveal a unique layer arrangement.

    Scientific model
  2. 2
    Fractured ice-rich crust

    Voyager images directly show cratered plains, giant scarps, grooves and lightly cratered coronae.

    Direct observation
05

How we know

Images constrain size, orbital and radio tracking constrain GM, and spectra and thermal emission constrain materials. Every number retains its method and limitation.

  1. 01

    Spacecraft imaging and shape reconstruction

    Repeated views reveal the limb, terrain, crater record and the shape used to estimate size.

    Where this method stops

    Lighting, viewing angle and incomplete coverage can hide topography. A mosaic is not a single untouched photograph.

    Direct observation
  2. 02

    Radio tracking and orbital dynamics

    Engineers measure spacecraft motion and moon orbits, solve for GM, and then derive mass and gravity.

    Where this method stops

    The result depends on trajectory coverage and a dynamical model. Very small moons leave weaker gravitational signatures.

    Calculated measurement
  3. 03

    Spectroscopy and thermal sensing

    The spectrum and thermal glow constrain surface materials, gases and representative temperature.

    Where this method stops

    A spectrum samples the visible surface or atmosphere. It does not directly photograph deep interior layers.

    Direct observation
06

Evidence key

Direct observation
An instrument or sample recorded the phenomenon, with processing still disclosed.
Calculated measurement
Observed motion or signal is converted into a physical quantity using equations and reference constants.
Scientific model
A tested interpretation that fits observations but is not directly imaged or sampled.
Vastward explanation
Original beginner-facing synthesis, traceable to the source records but not itself a measurement.
Artist visualization
An interpretive image, not observational evidence.
07

Missions and instruments

Active

Voyager 2

Voyager 2 made the only close Miranda flyby and returned the highest-resolution Uranian moon images, revealing its divided terrain.

Official mission ↗
Instruments
  • Imaging Science SubsystemImages the limb, terrain, color differences and time-dependent surface changes.
  • Spacecraft radio scienceMeasures Doppler and range changes that constrain trajectory, gravity and mass.
  • Infrared Interferometer Spectrometer and RadiometerSeparates light by wavelength to constrain composition, gases and temperature.
08

Official source trail

Links below are the exact records used for this profile. Access dates are retained with the content.

  1. 01

    NASA Science · official-page

    Miranda

    Source updated
    No source update date published
    Access checked
    2026-07-31
    Open official source ↗
  2. 02

    NASA Jet Propulsion Laboratory, Solar System Dynamics · dataset

    Planetary Satellite Physical Parameters

    Source updated
    No source update date published
    Access checked
    2026-07-31
    Open official source ↗
  3. 03

    NASA Science Photojournal · image

    Miranda - Highest Resolution Color Picture

    Source updated
    No source update date published
    Access checked
    2026-07-31
    Open official source ↗
  4. 04

    NASA Science · official-page

    Voyager mission

    Source updated
    No source update date published
    Access checked
    2026-07-31
    Open official source ↗
  5. 05

    NASA Technical Reports Server · research-paper

    Uranus Satellites: Surface Properties

    Source updated
    No source update date published
    Access checked
    2026-07-31
    Open official source ↗
  6. 06

    NASA Jet Propulsion Laboratory · official-page

    New Study of Uranus' Large Moons Shows 4 May Hold Water

    Source updated
    No source update date published
    Access checked
    2026-07-31
    Open official source ↗
09

Continue exploring

Atlas is a starting point. Use these relationships to move into explanation, experiment and mission thinking.

Available now

Understand moon systems

Place Miranda back inside Uranus's moon system and connect orbit, tides and resonance.

academy
Relationship reserved

Compare the major moons

Compare size, density, gravity and orbit without treating similar colors as identical composition.

lab