* Planets like Mercury, Venus, and Mars: These are all planets in our solar system.

* 11 letter word: We are looking for a word with 11 letters that describes planets similar to these.

The answer is: TERRESTRIAL

Why?

* Terrestrial planets are rocky planets, like Mercury, Venus, Earth, and Mars. They are characterized by:

* Solid, relatively dense surfaces

* A lack of rings

* Relatively few moons (compared to gas giants)

Let me know if you have any other word puzzles!