The center of a comet is called a “nucleus”.

 

The center of a comet is called a “nucleus”.

  

 

The streams of dust that streak behind comets are known as a “coma” or a “tail”. 

Space facts aren’t just about the planets! Here are some cool facts about comets. 

At the heart of every comet is a solid, frozen core called the nucleus. This ball of dust and ice is usually less than 10 miles (16 kilometers) across – about the size of a small town. When comets are out in the Kuiper Belt or Oort Cloud, scientists believe that’s pretty much all there is to them – just frozen nuclei.

But when a comet gets close to the Sun, it starts heating up. Eventually, the ice begins to turn to gas. This can also cause jets of gas to burst out of the comet, bringing dust with it. The gas and dust create a huge, fuzzy cloud around the nucleus called the coma.