Naming of moons to six moons and maybe even a ring. For nearly fifty years, Herschel's instrument was the only one the moons had been seen with. In the 1840s, better instruments and a more favourable position of Uranus in the sky led to sporadic indications of satellites additional to Titania and Oberon. Publications hesitated between William Herschel's designations (where Titania and Oberon are Uranus II and IV) and William Lassell's (where they are sometimes I and II). With the confirmation of Ariel and Umbriel, Lassell numbered the moons I through IV from Uranus outward, and this finally stuck. The first two Uranian
Solar System in fiction close to the Sun and its surface was exposed to extremes of temperature. The asteroids were too tiny and airless. By the early 20th century, prospects for life in the Solar System focused on Venus, the larger moons of Jupiter and Saturn, and especially Mars. With the onset of the Space Age, planetary probes cast increasing doubt on the likelihood of extraterrestrial life in the Solar System, at least life of any magnitude greater than organisms such as bacteria. By the mid-1960s, it was firmly established that life could have no foothold on the hostile surfaces of Mercury or Venus,