Planets are large, spherical bodies which orbit a star. Unlike stars, they do not have sufficiently high temperatures
in their cores to initiate thermonuclear reactions,
In 2006, the International Astronomical Union established a new definition of planet, which resulted in the
‘demotion’ of Pluto as a planet.
One interesting thing about the sizes of planetary orbits is that they seem to follow a fairly basic mathematical series known as
Bode’s Law.
