A mid-century modern gouache illustration of a small mountaintop astronomical observatory in a red rock desert at dusk, wide 16:9 landscape composition, painted in flat, opaque gouache with visible brush texture and slightly chalky matte color. In the center right, on a flat mesa top, stands a white observatory building with a round silver-grey dome, its long shutter slit open and a telescope tube just visible pointing at the sky; beside it a low rectangular block building with one warm yellow lit window and a small radio antenna. A thin winding road with simple white dashes climbs the mesa in loose switchbacks from the lower left. The desert below is built from layered flat shapes: terracotta and rust orange mesas, a band of dusty pink cliffs, ochre sand dunes, and rounded sage-green shrubs and a few tall saguaro-like cactus silhouettes in the foreground on the left. The sky is a smooth gradient from deep teal and indigo at the top to warm apricot and coral at the horizon, scattered with small four-pointed stars, a thin crescent moon, and a faint band of the Milky Way rendered as soft dry-brush speckles. Long purple shadows stretch across the sand. Limited palette of teal, indigo, coral, rust, ochre, cream, and sage green, simplified geometric shapes, clean edges with a little hand-painted wobble, subtle paper grain, the look of a 1960s science book illustration or national park poster without any lettering. Calm, optimistic, wonder-filled mood. No people, no text, no letters, no logos, no border, no watermark.