5$ Planets of the Solar System

In terms of the infinite space we call the 'universe', the Solar System is Earth's backyard. Only a fractional part of the Milky Way - one of billions of observable galaxies - it is still inordinately large.  

The formation of the Solar System began 4.6 billion years ago when an interstellar cloud of dust and gas began collapsing in on itself. Over millions of years, increasing pressure and temperature at the core of this material led to the creation of a star we call the Sun. 

With the effect of gravity, matter spinning around the core began clumping together. The largest of these masses became the Solar System's nine planets. Rocky versions, including the Earth, formed closest to the sun. Further away 

from the sun, gas and ice merged into four 'gas giants' - huge planets composed primarily of hydrogen and helium. 

The dwarf planet Pluto lies even more distant. Comprising a rocky core with an icy surface, it revolves around the sun at an average distance of 5.8 billion kilometres. 

The coin features a stylised impression of the Solar System. Portrayed in colour, the nine planets are aligned clockwise from the smallest to the largest in size: Pluto, Mercury, Mars, Venus, Earth, Neptune, Uranus, Saturn, and Jupiter. Other coloured elements include a comet and a depiction of the Sun as it might be seen from the rocky terrain of an orbiting asteroid. Both the asteroid and cosmic clouds in the background are finished with an antiqued surface treatment. 

The Ian Rank-Broadley effigy of Her Majesty Queen Elizabeth II is portrayed on the obverse of the coin, which includes its weight, purity, monetary denomination and year-date.