"Some explanations have suggested that the Lunarians set up advanced bridgeheads on Luna. This enabled their evident presence there to be reconciled with evolutionary origins on Minerva, but raised an equally problematical question: Why were they struggling to master interplanetary space-flight technology when they must have had it already? In the account I have described, this problem disappears. They had reached their own moon, but were still some ways from being able to move large populations to anyplace as remote as Earth. Also, there is now no need to introduce the unsupported notion of Lunarian colonies on either planet; either way, it would pose the same question.

"And finally, an unsolved riddle of oceanography makes sense in this light, too. Research into tidal motions has shown that catastrophic upheavals on a planetary scale occurred on Earth at about this time, resulting in an abrupt increase in the length of the day and an increase in the rate at which the day is further being lengthened by tidal friction. Well, the arrival of Minerva's moon would certainly create enormous gravitational and tidal disturbances. Although the exact mechanics aren't too clear right now, it appears that the kinetic energy acquired by Minerva's moon as it fell toward the Sun, was absorbed in neutralizing part of the Earth's rotational energy, causing a longer day. Also, increased tidal friction since then is to be expected. Before the Moon appeared, Earth experienced only Solar tides, whereas from that time up until today, there have been both Solar and Lunar tides."

Hunt showed his empty hand in a gesture of finality and pushed himself back in his chair. He straightened the pile of notes on the desk before going on to conclude:

"That's it. As I said earlier, at this stage it represents no more than a hypothesis that accounts for all the facts. But there are some things we can do toward testing the truth of it.

"For a start, we have a large chunk of Minerva piled up all over Farside. The recent material is so like the original Lunar material that it was years before anybody realized it had been added only recently. That supports the idea that the Moon and the meteorites originated in the same part of the Solar System. I'd like to suggest that we perform detailed comparisons between data from Farside material and data from the Asteroid surveys. If the results indicate that they are both the same kind of stuff and appear to have come from the same place, the whole idea would be well supported.