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Object profile · TITANIA

Titania

Largest moon of Uranus with a faulted ice crust

Uranus' largest moon, where enormous fault valleys show that the icy crust was stretched and broken.

Atlas data reviewed
Editorial stage
Published
Visibility
Public
Voyager 2 color composite of Titania showing craters and a large trench near the day-night boundary.Direct observation
Voyager 2 high-resolution color composite of Titania from violet and clear filter images.

Official multi-filter color composite. Surface detail is limited to about 9 km and the visible hemisphere is incomplete.

NASA/JPL ↗
Vastward explanation

What this world is

Titania's long troughs are cracks produced when the crust pulled apart. Bright material on some sun-facing walls may be frost, but the image does not reveal the deep interior.

Why it looks this way now

Voyager 2 directly saw impact scars and tectonic valleys. A 2023 thermal model makes Titania one of the stronger Uranian candidates for a residual briny ocean, still without direct detection.

02

Where it sits

The fourth of Uranus' five major moons, orbiting outside Umbriel and inside Oberon.

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 Titania among the profiled Uranus moon orbits.Scale one · Solar SystemUranusPlanet 7 from the SunSunScale two · Uranus moon systemUranusTitaniaProfiled orbit 4 of 5Mean distance · 436,298 km
Blue marks the current moon and orbit

Titania is 4 of 5 profiled Uranus moons by distance, at a mean center distance of about 436,298 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. Umbriel is the adjacent profiled moon inside; Oberon 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
788.9kmCalculated measurementThe mean radius is about 0.454 times the radius of Earth's Moon.

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

Published uncertainty: ± 1.8 km

JPL tabulated uncertainty for the adopted mean radius.

Massglobal mean
3.399607E21kgCalculated 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
1.6530g/cm³Calculated measurementDenser than Ariel and Umbriel and close to Oberon within uncertainty, consistent with a substantial rocky fraction.

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

Published uncertainty: ± 0.032 g/cm³

JPL tabulated uncertainty for the adopted mean density.

Reference gravitysurface
0.36458m/s²Calculated measurementRepresentative surface gravity is about 3.72% 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 modelThe displayed value is a sunlit system reference, while long seasonal darkness can be much colder.

A single reference cannot represent Titania's illuminated terrain, deep shadows and decades-long seasons.

Approximate value

Approximate sunlit upper reference near 85 K for Uranian moon terrain. It is not a measured global mean and does not represent polar night.

Orbit and rotation

Average distancesystem reference
436,298kmCalculated measurementThis is a representative center-to-center distance between Titania 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
8.705869Earth 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
8.705869Earth 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

Titania has no persistent atmosphere. Bright deposits are interpreted as surface frost, not clouds.

Surface and interior

Titania probably contains a large rocky fraction and water-rich layers below a faulted crust. A present ocean is model-supported, not observed.

  1. 1
    Modeled rock-rich interior

    Density and thermal evolution imply a substantial rocky fraction mixed with water-rich material.

    Scientific model
  2. 2
    Possible residual briny ocean

    Thermal modeling allows a salty liquid layer beneath the crust, but no instrument has directly measured it.

    Scientific model
  3. 3
    Faulted ice-rich crust

    Voyager images directly show craters, long fault valleys and possible frost deposits.

    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 supplied the only close Titania images, revealing ancient impacts and major crustal extension.

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

    Titania

    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

    Titania High-Resolution Color Composite

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

academyAvailable now

How do we detect a buried ocean?

Compare magnetic, gravity, plume and geology evidence while keeping ocean, habitability and detected life separate.

academy