Replies

Andrew Ellicott Douglass and the Big Trees
by Donald J McGraw
"[A]s early as 1729 the French biologist Comte de Buffon had suggested that tree rings record local weather history."
A Celestial Collision
by Larry Gedney
Early 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." The sighting of an asteroid strike on the moon, with an attendant brilliant flash, is an entirely believable possibility.
Evidence Of Tunguska-type Impacts Over The Pacific Basin Around The Year 1178 A.D.
by Emilio Spedicato
Was planet Earth, whose cross section is much larger than the Moon's (by a factor about 15), also impacted around the year 1178? Preliminary to this question: was the Earth crossing a stream around 1178? Then, if the Earth was hit, where was the event or the events and which were the consequences? Chinese astronomers, who were routinely recording comets and fireballs, show a very clear peak of sightings around the middle of the 12th century, the peak being over ten times higher than the average background. It is interesting to notice that a similar peak is also present at about half the 6th century, a time when, according to several Byzant[ine] historians quoted by Gibbon.

When the hidden face of the Moon was first photographed by a lunar mission, a large and clearly very recently produced crater was visible near the lunar north polar region. It was named the Giordano Bruno crater. Its recent origin is shown by the absence of secondary superimposed craters. The crater is considered to have been produced by a cometary or meteoritic impact with a body of 2-3 kilometers size, implying an energy in the range of hundred of million of megatons. The year of the impact might well be 1178 A.D., thereby explaining the observations recorded in the Canterbury annals, as first proposed apparently by Hartung.

By the above arguments, the following question naturally arises: was planet Earth, whose cross section is much larger than the Moon's (by a factor about 15), also impacted around the year 1178? Preliminary to this question: was the Earth crossing a stream around 1178? Then, if the Earth was hit, where was the event or the events and which were the consequences?

Some young up and comer published the ridiculous claim that had this 1178 AD event been an impact on the Moon, people everywhere would have reported unusually large numbers of shooting stars, and that since there are no such reports (that he's been able to find -- no doubt having combed all the surviving 12th century archives in multiple archaic languages, eh?) there must not have been an impact. The idea that such stupidity is still rewarded by a postgrad or postdoc degrees is a crime.

Meteor Stream Key To Earth's Climate
by Dr Victor Clube
Whipple and Hamid accurately retrocalculated the orbits of a number of meteors to indicate that several major fragmentations have taken place during the last five thousand years. The most significant of these events took place around 3000 BC due to an encounter in the asteroid belt; another was deemed to have occurred around AD 500, with possibly yet another in the second half of the second millennium BC. The epochs around 3000 and 1300 BC in particular correspond to significant deteriorations in the global climate for two or three centuries or more. It is known from other studies that a correlation exists between global rainfall and the incidence of meteor dust on the earth; so the indications now are for a considerable degree of climatic control by the Taurid-Arietid stream. Indeed, its giant comet is likely to have produced the last ice age whilst modulating the climate during the subsequent interglacial through the intermediary of stratospheric dust veils.
Rain of Iron and Ice
by John S. Lewis
On November 27,1919, a meteorite fell into Lake Michigan near the Michigan shore. "Residents of Battle Creek, Kalamazoo, South Bend, Grand Haven, and other Western Michigan cities fled from their homes in panic, fearing an earthquake. Houses were shaken, the country was illuminated as by a bright sun's rays, so all-enveloping it was impossible to tell from which direction the flare came, the earth trembled for half a moment and then came a deep prolonged rumbling as of a terrific explosion." (p 159)
Huge Fireball Explosion In 1994
by Dr Victor Clube
"It is therefore not surprising that the 10-meter-or-so asteroid that blew up over a largely vacant area of the western Pacific on February 1, 1994, producing an explosion equivalent to at least ten times that of the Hiroshima bomb (and possibly rather more), was not seen prior to impact. Surveillance satellites registered it as the brightest such explosion that they have picked up so far. Despite the efforts of numerous scientists in this area of study to make the military aware that such detonations do occur naturally, it appears that the U.S. President was awakened because the Pentagon thought that this incident might be a hostile nuclear explosion."
Wabar
The first date assigned to the event, based on fission-track analysis in the early 1970s of glass samples that found their way to the British Museum and the Smithsonian Institution, placed it about 6,400 years ago. The results from thermoluminescence dating, prepared by John Prescott and Gillian Robertson of the University of Adelaide, suggest that the event took place less than 450 years ago. [seen also in msg 29 of this thread]
Physics News Update
by Phillip F. Schewe and Ben Stein
New information about the mineralogical composition of the far side's crust was recorded and pictures revealed the largest impact basin yet seen on the moon, more than 2000 km in diameter and so deep that is may have penetrated through the crust to the moon's mantle.

And yet the Moon is moving away from the Earth.

Physics News Update
by Phillip F. Schewe and Ben Stein
Data from military satellites being made public for the first time reveal the scope of these meteoroid blasts: an average of 8 events a year were observed to have an energy equivalent to a small nuclear bomb, although the true occurrence may be 10 times larger. Much of the military data were originally gathered in an attempt to discriminate between meteoroid blasts and manmade nuclear explosions.