Night flight
From Wind, Sand and Stars:
No sum could buy the night flight with its hundred thousand stars, its serenity, its few hours of sovereignty.
A flock
If stars are eternal (relatively, next to the lifespan of a human) a passing flock of birds become all the more fleeting.
Lamplight
I am very fond of the lamplighter in The Little Prince, and the lamp here is a tribute to the character. But why is it unlit? Perhaps he is resting …
Salt lakes
I have always found images of the land mirroring the sky to be beautiful and strangely eternal in tone. This illustration was inspired in particular by photographs of salt lakes.

I hate this dissolvable humanity. Where I am, I am for all eternity.
If I sit down on a bench, I want to remain there for all eternity.
Sitting on my bench I am entitled to five minutes of eternity.
Antoine de Saint-Exupéry / Letter to Mme François de Rose (1944)