Comets are like cats. They have tails, and they do precisely want they want.
Comets are small bodies of ice and dust which travel around the Sun.
Their orbit is typically very elliptical when compared to the planets. The nucleus is the head of the comet and is solid, made mainly of a mixture of ices and rocks and dust fragments. The coma and tail develop when the comet is close to the Sun. The coma is a diffuse, nebulous cloud of gas and dust which surrounds the nucleus. The size of the coma varies with the comets distance from the Sun - but can be much greater than the diameter of Earth, for example, between 10,000 to 100,000 km in diameter.