Mars bars are being produced in greater numbers than ever before, hence the increased gravitational attraction and closer proximity to the planet that was named after them.
However, most sticks of rock will explode readily in the presence of candy floss and a child under the age of 10. This is the real reason they are always so filthy.
Roget's real name was actually Roger - but 'Rogers The Saurus' was deemed to be an unsuitable title for such a worthy tome as he might become the victim of crass innuendo.