Miranda

Miranda in astronomy, one of the moons, or natural satellites, of Uranus .

Miranda The fifth-largest satellite of Uranus, 481 × 468 × 466 km in diameter; also known as Uranus V. Its distance is 129 900 km and its orbital period 1.413 days, the same as its axial rotation period. Miranda was discovered in 1948 by G. P.Kuiper. As revealed by Voyager 2 in 1986, its icy surface has three very young areas of oblong parallel ridges and furrows unlike any other terrain in the Solar System, in some places heavily faulted at the edges, with cliffs over 15 km high. The rest of the visible surface is much older and cratered. The contrasts between the different types of terrain suggest that Miranda might have been broken up by a giant impact and then re-formed, with subsequent deformation producing faulting and ice flows.

Miranda (Uranus V) One of the major satellites of Uranus, discovered by Gerard Kuiper in 1948. Its radius is 240 × 234.2 × 232.9 km; mass 0.659 × 10²⁰ kg; mean density 1200 kg/m³; albedo 0.27; gravity 0.01 (Earth = 1); distance from Uranus 129 850 km. The surface temperature is about 43 K. Miranda is composed of rocky material and water ice in approximately equal proportions. The first pictures of the surface were provided in 1986 by Voyager 2 as it passed close to the satellite to gain a gravity assist to take it to Neptune. The surface of Miranda comprises areas of rolling, cratered terrain, with grooves, valleys, and cliffs, one more than 15 km high. Within this terrain there are three coronae. These are square, with rounded corners, up to about 260 km across, and contain dark and bright patches and sets of parallel ridges and grooves. It is now believed that the crust of Miranda was pulled apart by internal forces as the interior was evolving and the coronae formed above major upwellings of partially melted ice, and tidal distortions by Uranus caused heating.