SPOILERS from this point on! So go read the story first, it’ll take you all of thirty seconds.
Several years ago I read an article (and I regretfully do not recall its title, author, or where I read it–probably just something I stumbled across on the internet) suggesting that if we wanted to find artifacts and traces of a pre-human technological society we should look on the Moon.
Absent the eroding forces of wind and water, the artifacts of a society sufficiently advanced to reach the Moon might still be there, especially if any were placed in a location at least somewhat sheltered from the sun and meteor impacts. Now the constant solar wind, day/night temperature extremes (250/-200F), and rain of dust and meteors will certainly degrade anything left on the surface. But absent a direct meteor strike, the process proceeds far more slowly than what earthbound structures experience from endless wind, rain, freezing, thawing, and in the longer term, glaciation and plate tectonics.
This idea gave me the opportunity to write and publish my first dinosaurs in space story 🦖🌠
One could not expect a spacesuit and body to remain intact for sixty-five million years, but, perhaps it would still somewhat hold together after all that time. Particularly where this story is set…
That the view of the Earth is just above the horizon indicates this takes place near one of the Moon’s poles. Because the Moon is tidally locked to the Earth (it always shows the same face), the Earth doesn’t appreciably move from its position in the lunar sky. Though to be accurate, because the Moon’s tilt is slightly misaligned with regard to its orbit around the Earth, there is some movement, called the lunar libration, but the Earth essentially hovers at a fixed point in the sky. The lunar polar region makes sense for Moon exploration and settlement because the permanently shadowed craters–where the sun never shines–can became a collection point for water ice. If sunlight never reaches the base of the craters it won’t warm to those 250F temperatures. The ice that collects there, brought in from passing (or colliding!) comets over hundreds of millions of years can persist for eons.
An astronaut comes across an ancient, saurian predecessor resting against the base of a corroded lunar lander leg in one of these shadowed craters, where they’ve maintained a vigil for the last sixty-five million years. Presumably a marooned saurunaut would want the last thing they see to be their home world; yet in the astronaut’s present era it’s not visible through the gap in the crater wall.
The moon is slowly receding from the earth due to tidal friction at the rate of about 1.5″ (3.8 cm) per year. That’s not much, but it adds up over centuries, millennia, and millions of years. Earth and lunar day lengths have also shifted over time, which contributes to tiny misalignments between the Earth, a marooned saurunaut, and a gap in the wall of a lunar polar crater. Rewinding the clock to where the Earth would’ve appeared sixty-five million years ago from the bottom of a lunar crater is honestly perhaps a bit of a stretch–errors will add up in the estimations of how positions and velocities evolve over time.
But even if the estimate of the projected position of the Earth at the time of the Chicxulub asteroid strike that killed the dinosaurs is off by a bit, it’s no stretch to expect a lunar explorer to keep a final vigil over the home to which they could never return.