the equal number of terrestrial and Jovian planets (with the exception of Pluto) The age of the solar system can be established by radioactive dating of the oldest meteorites. read more
Jupiter, Saturn, Uranus and Neptune collectively make up the group known as the jovian planets. The general structures of the jovian planets are opposite those of the terrestrial planets. Rather than having thin atmospheres around relatively large rocky bodies, the jovian planets have relatively small, dense cores surrounded by massive layers of gas. read more