Post by Catsmate on Oct 14, 2014 11:48:08 GMT
This year on the Sunday before the Feast of Saint John the Baptist, after sunset when the moon was first seen, a marvellous sign was seen by five or more men sitting facing it. Now, there was a clear new moon, as was usual at that phase, its horns extended to the east; and behold suddenly the upper horn was divided in two. Out of the middle of its division a burning torch sprang, throwing out a long way, flames, coals and sparks. As well, the moon's body which was lower, twisted as though anxious, and in the words of those who told me and had seen it with their own eyes, the moon palpitated like a pummelled snake. After this it returned to its proper state. This phenomenon was repeated a dozen times or more, the flame assuming various twisting shapes at random and then returning to normal. Then, after these transformations, the Moon from horn to horn, that is along its whole length, took on a blackish appearance. This to me who writes this was told by those men who with their own eyes saw it, and who are willing to swear an oath that they have not added to nor falsified the above written.
What exactly Gervase's five monks, saw just after sunset on Sunday the 18th of June 1178 isn't certain. There are two competing theories. That they saw something is virtually certain; Gervase's Chronicles are generally accurate, and his two other astronomical notations (on a fireball and an eclipse) are verified by other sources.
- It was June the 18th by the Julian calendar, the 25th by the Gregorian.
Firstly that they witnessed the impact of a large asteroid, perhaps 2km across and massing 5-10 billion tonnes, on the surface of the moon, creating the relatively young crater Giordano Bruno at the impact site. This was first proposed by J. B. Hartung in 1976. It's possible the impact was part of Encke's Comet, as suggested by Ken Brecher, who also suggested it was part of what he called the "Canterbury Swarm" of cometary bodies, that may also have caused the Tunguska blast and other impacts.
The main problem with this is that the Giordano Bruno crater is almost certainly older that 800 years, as shown by spectrometric studies. Further, an impact sufficient to create a 22km crater would have ejected millions of tonnes of material to rain down on the Earth; at the very least such debris would have created a global lightshow that would have been well documented.
The second theory is that the monks saw a meteor explode high in the Earth's atmosphere, fortuitously aligned so it appeared to impact the moon. This is reasonably plausible, geometric perspective would mean that only a small area in Britain would have the alignment to make it look like it was on the Moon.
Gaming potential.
As the Whoniverse doesn't need to be too bound to historical or physical reality this event has some interesting possibilities.
Firstly the PCs could arrive in Canterbury, for whatever reason, and hear of the incident. It shouldn't be too difficult to pique their curiousity and have them investigate, leading into whatever plot the GM has planned.
Secondly if indeed something did impact the moon, either in an existing crater or creating a new one, what was it? A lump of rock, ice and metal randomly travelling the cosmos? Or a spacecraft directed by intelligent beings?
- Perhaps a Silurian ark returning to Earth, and suffering a catastrophic navigational error.
Thirdly if it was a simple asteroid impact, what happens if someone tampers with its course? The Cybermen planned to divert Halley's Comet to strike Earth, perhaps they (or another species) try again with an earlier event. Potentially also involving other time travellers from Earth's future (the Time Agency perhaps?) trying to stop them. With the PCs stuck in the middle.
- The impact of such an object, delivering perhaps 100,000 megatonnes equivalent, would be an extinction level event. Assuming an impact in the northern Atlantic Ocean (given it misses the Moon above Canterbury) a 150m tsunami would have scoured the coastal portions of the Americas, Europe and the Mid East clear of life. Humanity would have survived, but global climate would have changed catastrophically.
Alternatively tampering with the asteroid could have been an attempt by an alien species to render Earth more suitable for colonisation, at the cost of the native life. A desperate act by the otherwise doomed survivors of a dead planet perhaps, or simply clearing off potentially irritating primitives who might interfere with a new colonisation effort by an expansionist species. The time travellers could land anytime after the impact and have to track down the interference with human history.
References.
Gervase of Canterbury
Gervase's works are available online.