Logic's a wonderful thing; by logical analysis, one can determine the necessary reason for the existence of a dead city of a very high order on an utterly useless planet. Obviously a shipping transfer point! Necessarily...
ted by its inhabitants at an unknown time in the past.
That's right--deserted. There were no signs of any remains of living things. They'd all simply packed up and left, leaving everything behind.
Dating by the radiocarbon method was useless. Some of the carbon compounds in the various artifacts showed a faint trace of radiocarbon, others showed none. But since the method depends on a knowledge of the amount of nitrogen in the atmosphere of the planet of origin, the rate of bombardment of that atmosphere by high-velocity particles, and several other factors, the information on the radioactivity of the specimens meant nothing. There was also the likelihood that the carbon in the various polymer resins came from oil or coal, and fossil carbon is useless for radio-dating.
Nor did any of the more modern methods show any greater success.
It had taken Man centuries of careful comparison and cross-checking to read the evolutionary history written in the depths of his own planet's crust--t
A domed, abandoned alien city is discovered on an uninhabitable Centaurus planet. The artifacts are a scientific windfall. But why was it abandoned? Where are the aliens?
The story eventually reveals the answers, but first the narrator has to find his mentor and do some interstellar traveling. I personally didn't find the astounding revelation at the end to be worth the trip through the story.