J. B. Plescia 1987 <p>The southern hemisphere of Ariel, a satellite of Uranus, can be divided into several terrain types. Data on the size-frequency distribution of craters for those different terrain types indicate that these terrains formed over a relatively short period of time. Much information on Ariel's geological history can be gained from these data.&nbsp;</p> application/pdf 10.1038/327201a0 en Springer Nature Geological terrains and crater frequencies on Ariel article