Choose the correct collective noun from the options below and fill in the blanks.

The ____ of planets in our solar system is fascinating.

Cluster

The correct collective noun for a group of planets in our solar system is "Cluster." OPTION 2

Explanation:

Assembly typically refers to a group of people gathered for a purpose.

Fleet usually refers to a group of ships or vehicles.

Galaxy refers to a massive system of stars, interstellar gas, dust, and dark matter.

Cluster is a suitable term for a group of celestial objects like planets that are relatively close together.

So, the correct sentence would be: "The cluster of planets in our solar system is fascinating."