Posted on 02/03/2004 2:54:24 PM PST by ckilmer
Public release date: 3-Feb-2004
Contact: Dr Derek Ward-Thompson derek.ward-thompson@astro.cf.ac.uk 029-2087-5314 Cardiff University
Astronomers unravel a mystery of the Dark Ages Undergraduates' work blames comet for 6th-century "nuclear winter" Scientists at Cardiff University, UK, believe they have discovered the cause of crop failures and summer frosts some 1,500 years ago a comet colliding with Earth. The team has been studying evidence from tree rings, which suggests that the Earth underwent a series of very cold summers around 536-540 AD, indicating an effect rather like a nuclear winter.
The scientists in the School of Physics and Astronomy believe this was caused by a comet hitting the earth and exploding in the upper atmosphere. The debris from this giant explosion was such that it enveloped the earth in soot and ash, blocking out the sunlight and causing the very cold weather.
This effect is known as a plume and is similar to that which was seen when comet Shoemaker-Levy-9 hit Jupiter in 1995.
Historical references from this period - known as the Dark Ages are sparse, but what records there are, tell of crop failures and summer frosts.
The work was carried out by two Cardiff undergraduate students, Emma Rigby and Mel Symonds, as part of their student project work under the supervision of Dr Derek Ward-Thompson.
Their findings are reported in the February issue of Astronomy and Geophysics, the in-house magazine of the Royal Astronomical Society.
The surprising result of the new work is just how small a comet is needed to cause such dramatic effects. The scientists calculate that a comet not much more than half a kilometre across could cause a global nuclear winter effect. This is significantly smaller than was previously thought.
Dr. Ward-Thompson said: "One of the exciting aspects of this work is that we have re-classified the size of comet that represents a global threat. This work shows that even a comet of only half a kilometre in size could have global consequences. Previously nothing less than a kilometre across was counted as a global threat. If such an event happened again today, then once again a large fraction of the earth's population could face starvation."
The comet impact caused crop failures and wide-spread starvation among the sixth century population. The timing coincides with the Justinian Plague, widely believed to be the first appearance of the Black Death in Europe. It is possible that the plague was so rampant and took hold so quickly because the population was already weakened by starvation.
Ahh yes.. SG-1, where we can learn all sorts of things. Especially how a fine looking lady handles a P-90. For instance: notice the proper "safe" grip.
Nah. Those are just little hiccups.
Here are the dates for worldwide affecting events as recorded by tree rings: 3195BC, 2354BC, 1628BC, 1159BC, 540AD and two smaller events at 207BC and 44BC.
Check your history books and see what was happening in the world at those times.
Celtic Sea: http://visibleearth.nasa.gov/data/ev54/ev5435_S1998140125834_md.jpg
Yup. I've read that the kings had writers and readers and the writers could not read and the readers could not write. (Doesn't make a lot of sense but, that's what I read)
Our custom of reading wills aloud comes from that period. Everything official used to be read aloud because so few could read.
Yep........I remember it, too. Cold as all hell, it was.
So it was a comet made of carbon? Or did it wipe-out a uge forest?
New Light On Dark Age
By Roger Highfield
Science Editor
The Telegraph - UK
2-4-4
A monk's apocalyptic book and Arthurian legend are united by a study that shows how a comet plunged Britain into a dark age in the sixth century.
Studies of tree rings showed the Earth underwent a series of very cold summers around 536-540 AD, a Cardiff University team reports in the journal Astronomy and Geophysics. They believe the chill was caused by a comet exploding in the Earth's upper atmosphere.
Historical references from the Dark Ages are sparse, but what records there are tell of crop failures and summer frosts. Gildas Bandonicus, a Celtic monk, in his book Concerning the Ruin of Britain (De Excidio Britanniae) recorded that "the Sun gave forth its light without brightness".
Folklore also suggests that the death of King Arthur - in either 539 or 542 depending on your source - plunged Britain into a dark age. Merlin, Arthur's magician, is depicted in mythology as a "red fiery whooshing dragon flying in the sky" - an account consistent with a comet impact.
© Copyright of Telegraph Group Limited 2004.
(I think the Angel Gabriel was a comet or asteriod that fell into southern Iraq in 2200-2300BC, a fragment from this impact was given to Mohammad by Abraham and is the stone the Islamists presently worship in Mecca)
Lowered temperatures made Roman Senators stab Caesar in the forum (and duodenum)?
Long term survival of our species depends on spreading out though the stars.
The only defense against the larger objects, which will hit any planetary body,
is to not have all our eggs in one basket.
You think responding to natural disasters is a responsibility of DOD?
Gimme a break. NASA's job is whatever Congress says it is.
Elimination of an incoming object either missile or comet is much better suited to DOD.
NASA wouldn't be my first choice to handle an earthquake either.
FEMA comes to mind for that.
Please don't misunderstand, I don't dislike NASA. They should be doing space exploration.
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