What is the origin of the idiom "a trip to the sun" and when to use it?

The phrase "a trip to the sun" is an idiomatic expression that signifies an impossible or absurd endeavor. It's used to emphasize that a proposed action or idea is so unrealistic or unattainable that it's akin to suggesting a journey to the sun, which is physically impossible. The origin of this phrase is not precisely documented, but it likely developed from the impracticality of reaching the sun due to its extreme heat and the technological limitations of space travel.