In the lee of the crater rim, something sparkled, something that finally banished the lunar ghosts of Armstrong and Muldoon from this moment, something that made her feel that her life’s circle had closed, at last. I guess I got to step into the picture after all.

It was frost.

She leaned sideways, and stretched down to the crater’s floor, awkwardly. She scraped at the dust with her fingers. Her fingers cut easily into the surface, leaving sharp trench marks. I’m like a kid, digging on a beach. A planetwide beach. Everywhere she dug, she found the same soft, powdery surface, the same cohesiveness, what looked like pebbles.

She lifted her glove to her face, to get a closer look at the dirt. It was oddly frustrating. The bit of regolith was very light, so light she couldn’t even feel its weight. She couldn’t even feel its texture because of the thickness of her clumsy suit. And the glare of the rising sun in her glass faceplate made it difficult to see, and the whir of pumps, the hiss of the radio, cut her off from whatever thin sounds were carried by the Martian winds.

She had a sense of unreality, of isolation. She was here, but she was still cut off from Mars. It wasn’t like a field trip at all.

She closed her fingers over the sample; the little “pebbles” burst and shattered. They were just fragments of a calichelike duricrust.

She tipped her hand and let the crushed dust drift back to the surface; much of it clung to the palm of her glove, turning it a rust brown.

She took the diamond marker out from the sample pocket on her suit. She held the little coin in her hand; it caught the sunlight and refracted it, turning its glow to a bright scarlet, jewellike, against the ocher of Mars.

She felt a sudden, and unexpected, surge of pride. She distrusted patriotism intensely; and maybe this expedition, these few days of scrambling over Mars like rabbits, really was all a grand technocratic folly. But the fact was that her country had — in little more than two centuries of existence — sent its citizens to walk on the surfaces of two new worlds.

And if some calamity were to wipe Earth clean of life before anyone decided to come again, this little marker, with its flag, would still be here, as a monument to a magnificent human achievement: this, and the remnants of Challenger, and three Lunar Module descent stages on the surface of the Moon.

And to think we nearly didn’t come here; to think, after Apollo, we might have closed down the space program.

Carefully she dropped the marker and let it float through the weak gravity down into the hole she’d dug, where it lay, sparkling, in the base of the crater.