Titania is the largest moon of Uranus, though at 1,577 km across it is still less than half the size of our Moon. Voyager 2 revealed a cratered gray-brown surface torn by enormous fault canyons - evidence that the moon’s interior once expanded and cracked its own crust.
Messina Chasmata, its largest canyon system, runs roughly 1,500 km - about a third of the way around the moon.
William Herschel spotted it in 1787, six years after he discovered Uranus itself.
Though it is Uranus’ largest moon, it holds only about 1/20 the mass of our Moon.
A crust cracked from within
Water does something unusual when it freezes: it expands. As Titania’s interior slowly froze over billions of years, the growing ice pushed outward on the crust, stretching it until it fractured into vast canyon systems like Messina Chasmata. The scars of that ancient freeze are a reminder that ice is not just a surface coating out here - it is the structural rock of the outer Solar System.
Physical characteristics
Diameter
1,577 km
Mass
3.500e+21 kg
Surface gravity
0.38 m/s²
Density
1.71 g/cm³
Tidally locked
Yes
Mean temperature
-200 °C
Geometric albedo
0.27
Atmosphere and composition
Atmosphere
None detected.
Composition
Roughly half water ice and half rock, likely differentiated into a rocky core and icy mantle.
Discovery
Discovered by
William Herschel
Year
1787
How
his own 18.7-inch reflecting telescope
Missions
Voyager 2NASA · Flyby probe · 1977 · active
Launched 16 days before its twin, Voyager 2 is the only spacecraft ever to visit all four giant planets - Jupiter, Saturn, Uranus and Neptune. It entered interstellar space in 2018 and is still returning data.