History of Solar System formation and evolution hypotheses the asteroids. Terrestrial planets would have no major moons which does not account for Luna. It predicts certain observations such as the similar angular velocity of Mars and Earth with similar rotation periods and axial tilts. In this scheme there are 6 principal planets: 2 terrestrial, Venus and Earth, 2 major, Jupiter and Saturn, and 2 outer, Uranus and Neptune; and 3 lesser planets: Mercury, Mars, and Pluto. This theory has a number of problems, such as explaining the fact that the planets all orbit the Sun in the same direction, which would appear highly unlikely if they were each
The Science of Aliens possibilities for alien life. The second section explores the variety of life on Earth and the extreme conditions in which it can survive. It looks at recent missions to moons and planets in the Solar System and what they can tell us about alien life before going on to examine some extra-solar planets. The next section presents two fictional planets, Aurelia and Blue Moon and their ecosystems as imagined by scientists. These are used to explore the factors and parameters governing life on other planets and are presented as two large interactive landscapes. The exhibition concludes by looking at the