What are Comets?
Comets are cosmic iceballs composed of dust and frozen gases in concentrations that place them in the category of what is known as ‘small Solar System bodies’. Comets range from a few metres in diameter to up to tens of kilometres. They are characterised by a glowing head and a tail made of dust and gas that points away from the Sun.

Comet Historical Figures
Comets were considered to be bad omens within ancient societies. Records suggest that some people believed that comets were messengers of gods and others thought they were signifiers of bad luck, crashing ships and natural disasters. Although these theories have since been disproved, these views once held true across the ancient civilisations of Greece, Rome and China.

The Science Behind Comets
Comets are usually parts of a wider ‘family’ of comets called the short-period comets, which take less than about 200 years to travel around the Sun. Longer-period comets take up to thousands of years to orbit the Sun. Every comet contains a nucleus as its central part, with a certain amount of ice and dust surrounding it, along with gas. When a comet enters the solar system, the solar wind and radiation begins to act upon it and this causes the outer part of the comet to sublimate and be released as vapour. This vapour then gets ionised and is detached away from the comet in the form of a tail. When this matter evaporates, it leaves a dark core of dust and ice particles.

The composition of a comet’s nucleus is mostly made up of dust, ice, and gas, composed of grains of carbon dioxide, carbon monoxide and methane. The presence of this dust, gas and other molecules makes comets unique in comparison to other objects within the Solar System. The formation of comets is often linked to the formation of the Solar System, but their exact origins remain a mystery.