Beyond the Moon

Abstract

We now look beyond the Earth–Moon system to see how impacts are shaped throughout the Solar System.8,9 In Chapter 1, I gave a brief overview of worlds (in the form of images) showing how widespread cratering is from Mercury to Triton, and related this to the most widely accepted theory of the evolution and development of the Solar System. We also saw how this evidence provides clues into the evolution of our local planetary system to its present form. We saw how a huge impact likely led to the formation of the Moon and how impacts shaped the surfaces of the worlds in the early history of the Solar System. Impacts are also considered to be responsible for the retrograde (backwards) rotation of Venus, the high metal content in Mercury, the dichotomy in landforms on Mars, the rings of Saturn, and the extreme axial tilt of Uranus. One of the moons of Uranus, Miranda, appears to have been broken up by a large impact, but something unusual happened after the impact: the object pulled itself together again to become one body.