Rings of Rhea dips bear some similarity to the method by which the rings of Uranus were discovered in 1977. The slight deviations from absolute symmetry may be due to "a modest tilt to the local magnetic field" or "common plasma flow deviations" rather than to asymmetry of the rings themselves, which may be circular. Not all scientists are convinced that the observed signatures are caused by a ring system. No rings have been seen in images, which puts a very low limit on dust-sized particles. Furthermore, a ring of boulders would be expected to generate dust that would likely have been seen
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,