I don't know if there is someone keeping a running list of Project Target ideas to pick from, but the origins of Earth's moon Luna would be a very interesting one.
Our Moon has many unusual characteristics that have led some researchers (and a number of speculative theorists) to propose unconventional origins. For example:
-The Moon is unusually large relative to its planet — about ¼ of Earth’s diameter.
Most moons in the solar system are tiny compared to their planets.
-Its orbit is almost perfectly circular and aligned near the ecliptic rather than Earth’s equatorial plane — atypical for a captured body and somewhat odd for an impact-formed one.
-The Earth–Moon barycenter (center of mass) lies inside Earth but not at its core — unique among known large planet–moon systems.
-The Moon’s mean density (3.34 g/cm³) is much lower than Earth’s (5.5 g/cm³), suggesting it lacks a large iron core. Yet, isotopic analyses (especially oxygen isotopes) show the Moon’s material is nearly identical to Earth’s mantle, implying a common origin — but the ratios are too similar to easily explain by an impact from a chemically distinct body.
-There’s a puzzling iron distribution: the near side has a thinner crust and more maria (basaltic plains) than the far side.
-The Moon is tidally locked, always showing the same face. That’s not unique, but combined with its size and distance, it’s an incredible coincidence that it perfectly covers the Sun during total eclipses — the only known case in our solar system. This geometric precision has been cited by some as too convenient to be accidental.
-Apollo seismometers detected that the Moon “rang like a bell” after impacts — vibrations persisted for up to an hour, much longer than expected. NASA scientists attributed this to the Moon’s dry, fractured structure, but it’s still sometimes mentioned as evidence for an unusual interior composition — even “hollow Moon” hypotheses.
-Some lunar rocks appear older than Earth’s oldest rocks, possibly remnants of the early solar system crust. How can that be if the current theory is the Moon came from an Earth impact?
-The distribution of craters (more on the far side, fewer on the near side) and the thickness variation of the crust are difficult to explain entirely by impact mechanics.
-If the Moon had been captured, it should have:
*An extremely elliptical orbit (it doesn’t).
*A different isotopic signature (it doesn’t).
Yet, a perfect capture into a stable, nearly circular orbit without significant atmospheric braking seems improbable — unless something “assisted” the process.
And if it was placed into Earth's orbit to create seasons with the desired result to spur evolution here, what kind of species is operating at those kinds of levels and technology, where are they now and if they are still around, what are they up to today?