Voyager 2 images of the five largest moons of Uranus,taken on Jan 20,1986. From left,in order of increasing distance from the planet: Miranda,Ariel,Umbriel,Titania & Oberon. The two largest,Oberon & Titania,are about 1600km diameter. Miranda,the smallest of the five,is about 500km in diameter. The satellites exhibit distinct differences in appearance. On average,Oberon & Titania reflect 20% of incident sunlight,Umbriel 12%,Ariel & Miranda 30%. Ariel shows the greatest contrast on its surface,from 45% reflectance to 25%. All satellites show only slight colour variation on their surface & appear uniform grey |