A Celestial CollisionEarly in the evening of June 18, 1178, a group of men near Canterbury, England, stood admiring the sliver of a new moon hanging low in the west. In terms they later described to a monk who recorded their sighting, "Suddenly a flaming torch sprang from the moon, spewing fire, hot coals and sparks." In continuing their description of the event, they reported that "The moon writhed like a wounded snake and finally took on a blackish appearance"... [P]lanetary scientist Jack Hartung of the State University of New York... gathered enough clues to suggest that a large asteroid... might have smacked into the moon just over the horizon on the back side. To test his suspicion, Hartung went to the Lunar and Planetary Institute in Houston, and inspected Russian and American photographs of the moon's back side. Sure enough, in just the right place, he found a remarkably fresh crater, 12 miles across and twice as deep as the Grand Canyon. From it radiated white splatter marks for hundreds of miles... Such an impact, reason astrophysicists, would set the moon to ringing like a gong for thousands of years... At Texas' McDonald Observatory, astronomers Odile Calame and J. Derral Mulholland of the University of Texas find that the surface of the moon moves back and forth fully 80 feet! Such an oscillation clearly implies a collision with something large, sometime within the not-too-distant past, probably within the memory of mankind. The problem is that there is no way to peg the date exactly at 1178.
by Larry Gedney
February 10, 1983
That’s fascinating. I assume the moon’s core is solid?