* Comets: Comets are generally the smallest. Their nuclei, the solid icy heart, can be as small as a few kilometers in diameter, and some are even smaller.
* Asteroids: Asteroids can range in size from a few meters to hundreds of kilometers in diameter.
* Moons: Moons are typically larger than comets and many asteroids. The size of a moon can vary greatly. For example, our Moon is quite large, but many moons around other planets are smaller.
* Planets: Planets are the largest objects in our solar system, with diameters ranging from a few thousand to tens of thousands of kilometers.
It's important to note:
* There's a lot of overlap in size between these categories. Some asteroids are bigger than some moons, and some moons are bigger than some planets.
* We're constantly discovering new objects in space, and our understanding of their sizes is constantly evolving.
So, in general, you can say that comets are often the smallest, followed by asteroids, then moons, and finally planets.
