Solar eclipses on Uranus Umbriel, Titania and Oberon—are large enough and near enough to eclipse the Sun. All other satellites of Uranus are too small or too distant to produce an umbra. At its distance from the Sun, the Sun's angular diameter is reduced to a tiny disk about 2 arcminutes across. The angular diameters of the moons large enough to fully eclipse the sun are: Cressida, 6–8'; Desdemona, 6–7'; Juliet, 10–12'; Portia, 9–13'; Rosalind, 4–5'; Belinda, 6–8'; Puck, 6–8'; Miranda, 10–15'; Ariel, 20–23'; Umbriel, 15–17'; Titania, 11–13'; Oberon, 8–9'. Solar eclipses on Uranus Solar eclipses on Uranus occur when any of the natural
Mars trilogy help them better adapt to the new worlds; to breathe thinner air (e.g. Russell), or to see better in the dimmer light of the outer planets. The books also speculate on the colonization of other planets and moons in the Solar System, and include descriptions of settlements or terraforming efforts on Callisto, Mercury, Titania, Miranda and Venus. Toward the end of the last novel, humans are taking sub-light colony ships to other stars, taking advantage of the longevity treatments to survive the trip to their destinations. A great portion of "Blue Mars" is concerned with the effects of extreme longevity