The Moon stood still for twelve hours
On November 6, 2010 I posted a theory that Mare Moscoviense on the far side of the Moon is the result of overlapping impacts from comet fragments. The image above highlights what I think are four of the major impacts. So far, I am the only person who believes in this idea.
On the one hand, geologists are of the opinion that impacts have to retain specific shock characteristics from the high impact forces. The reason for this is that, on Earth, many volcanic features can be easily confused with impact craters, and the shock characteristics can help to differentiate between volcanic and impact features. This works fine when a single isolated impact is involved, but the criteria do not take into consideration multiple overlapping impacts which would be very different because impacts after the first would fall on a surface melted by a previous impact.
A second prevalent idea is that ancient craters can be flooded by lava so that only the rims remain visible. This may be true, but impacts on viscous fluids also produce what appear to be "flooded craters", but this mechanism has never been considered because impacts by a cluster of impactors would be a very remote possibility. In 1994, we saw the fragments of comet Shoemaker Levy 9 strike Jupiter, so the possibility of multiple impacts is small, but real. Unfortunately, Jupiter is a gas giant; there were no impacts on a solid surface that we could use for comparison.
In trying to make the case for an impact origin for Mare Moscoviense, I have tried to identify the characteristics that would differentiate volcanic lava from impact lava. Interestingly, the 40,000 square kilometers covered by Mare Moscoviense are very smooth and there does not seem to be any volcanic cone from which such a great quantity of lava could have come. I have also experimented with impacts on soft clay to show that these impacts may have some morphological similarity to impacts on molten rock. I then estimated the volume of molten lava in Mare Moscoviense and calculated that the proposed impacts could have had enough energy to melt all that rock. The last thing that I accomplished was to identify a viable collision trajectory between a string of cometary fragments and the Moon. In this trajectory, the Moon appears to remain still for at least a period of 12 hours while the string of fragments has the opportunity to hit the Lunar surface repeatedly in the same location. The figure below shows a tangential collision during the first quarter or third quarter Moon that fulfills these requirements.
Several months ago, I notified two of the main Japanese scientists who worked on the KAGUYA Lunar mission about my theory, but I have not received a reply. I expect that many years will pass before this idea is considered seriously.
 Morota, T., et al., 2009-b, Ages and Thicknesses of Mare Basalts in Mare Moscoviense: Results from SELENE (KAGUYA) Terrain Camera Data, 40th Lunar and Planetary Science Conference, (Lunar and Planetary Science XL), held March 23-27, 2009 in The Woodlands, Texas, id.1280
© Copyright - Antonio Zamora