Oberon (moon) toward the planet. Oberon spends a significant part of its orbit outside the Uranian magnetosphere. As a result, its surface is directly struck by the solar wind. This is important, because the trailing hemispheres of satellites orbiting inside a magnetosphere are struck by the magnetospheric plasma, which co–rotates with the planet. This bombardment may lead to the darkening of the trailing hemispheres, which is actually observed for all Uranian moons except Oberon (see below). Because Uranus orbits the Sun almost on its side, and its moons orbit in the planet's equatorial plane, they (including Oberon) are subject to an extreme
Titan (moon) Titan (moon) Titan is the largest moon of Saturn. It is the only moon known to have a dense atmosphere, and the only object in space, other than Earth, where clear evidence of stable bodies of surface liquid have been found. Titan is the sixth gravitationally rounded moon from Saturn. Frequently described as a planet-like moon, Titan is 50% larger than Earth's moon and 80% more massive. It is the second-largest moon in the Solar System after Jupiter's moon Ganymede, and is larger than the smallest planet, Mercury, but only 40% as massive. Discovered in 1655 by the Dutch astronomer