Titania

Uranus's largest moon

Titania is Uranus's biggest moon, but it's half the size of our Moon. It is made of ice and rock, and its surface has giant canyons — as if someone had slashed it with a knife. Titania is very cold: −200 degrees! Ice there is harder than rock.

Titania (radius 788 km) is Uranus's largest moon and the eighth largest in the Solar System, orbiting every 8.7 days. It was discovered by William Herschel in 1787. Its surface is cratered but cut by giant canyons (Messina Chasma — 1,500 km long): the crust cracked as the interior froze and expanded. The surface is a mix of ice and dark organic material. Because Uranus's axis is tilted 98°, Titania also orbits 'on its side' — each pole faces the Sun for 42 years at a time. Voyager 2 flew past in 1986 at 365,000 km; NASA is planning a Uranus orbiter mission.

Fun facts

• Titania was discovered in 1787, but photographed only 200 years later.
• On Titania a pole gets 42 years of daylight, then 42 years of night!
• Titania's canyon is 3 times longer than the Grand Canyon.