When the atmosphere becomes the bottleneck, not the glass

Last month I was out in the Mojave trying to pull detail from a distant ridge formation against the Milky Way core. Swapped to a longer focal length expecting sharper silhouettes and more separation in the rock features. The result looked softer than what I'd gotten at a wider focal length earlier in the night.

Turns out the culprit was residual heat radiating off the desert floor. Even hours after sunset, the thermal turbulence was smearing fine detail in a way no amount of focal length could fix. I've noticed the same thing on humid nights near Anza Borrego, where low altitude haze eats contrast before the lens even factors in.

For those of you shooting distant subjects at night or during twilight, have you found conditions where the atmosphere just wins? I'm curious whether anyone has developed a reliable way to read the conditions before committing to a longer focal length setup, or if it's mostly trial and error once you're on location.