Something like a tummy rub for your eyes.
Alpenglow is that rosy radiant shine that certain mountains adopt shortly before sunset.
People with fancy diplomas will tell you this is the result of the low angle evidenced by evening sunlight, which shines through miles and miles more atmosphere than, say, noontime sunlight, thereby having its other colors stripped away by dust, water vapor, and so on.
But did you ever think that this could be another phenomenon entirely? That, toward the end of the day, as the earth continuously turns, it may simply be that the tops of certain mountains (the highest of course) have managed to warm up to the point that they glow a dull pink, by rubbing against the sky?
Certainly, this is apparent only at sunset (very, very rarely at sunrise), but that is because sunlight itself, even though filtered through the atmosphere, adds just enough extra energy to stimulate this effect.
That is why you see no alpenglow at night, when things are cooler, and why, if humans ever undertake a trip to the sun, they should be sure to try it only at night.