"Comet ball" is not a standard astronomical term. It is likely a colloquial term used to describe a comet's nucleus.
What is a Comet's Nucleus?
A comet's nucleus is the solid, icy body at the heart of a comet. It's essentially a dirty snowball, made up of:
- Ice: Water ice, as well as frozen gases like carbon dioxide, methane, and ammonia.
- Dust: Rock, metal, and other small particles.
Why is the Nucleus Important?
The nucleus is the source of all the activity we see in a comet. As it gets closer to the Sun, the ice begins to sublimate (turn directly from solid to gas). This process releases gas and dust, creating the characteristic tail that we see.
Examples of Comet Nuclei
- Comet Halley: One of the most famous comets, with a nucleus about 11 km in diameter.
- Comet 67P/Churyumov-Gerasimenko: The target of the Rosetta mission, which landed a probe on its surface.
Conclusion
While "comet ball" is not a formal astronomical term, it likely refers to the comet's nucleus, the icy core that drives all the activity we see.
