The term "astronomical fee" is a figurative expression used to describe a fee that is extremely high or excessively large. It is meant to emphasize the sheer magnitude of the cost, implying that it is so high it seems out of this world, like the vastness of space.

The expression does not refer to a specific type of fee related to astronomy or space exploration. It's simply a way to express the feeling that a fee is unreasonably expensive.

Here are some examples of how the term might be used:

* "They charged me an astronomical fee just to fix a minor scratch on my car."

* "The hotel's room rates were astronomical during the holidays."

* "The consultant's fees were astronomical, but his expertise was invaluable."

It's important to remember that "astronomical fee" is a subjective term. What is considered astronomical to one person may not be to another.