To: bpr-list@philologos.org (BPR Mailing List)
Subject: [BPR] - (resend) Sept 17, 1999 TV Programs
From: bpr-list@philologos.org(BPR)
Date: Fri, 17 Sep 1999 08:31:59 +0000

From: "Moza" <moza@butterfly.mv.com>

8:00 PM Eastern

 HIST - PROPHECIES - Civilizations seek their destinies
   through prophetic visions.(CC)(TVG)

9:00

 DISC - DISCOVERY NEWS - (CC)

 HIST - HIGH ROLLERS: A HISTORY OF GAMBLING - The evolution
   of gaming in the United States.(CC)(TVPG)

10:00

 DISC - NAPOLEON'S LOST FLEET - Marine archaeologists search
   for Napoleon's battleship, L'Orient, in the
   Mediterranean.(CC)(TVG)

 TLC - ANCIENT ASTRONAUTS - Shamans convey wisdom with
   mental journeys between Earth and the
   heavens.(CC)(TVG)

========
To: bpr-list@philologos.org (BPR Mailing List)
Subject: [BPR] - Small but deadly comets identified
From: bpr-list@philologos.org(BPR)
Date: Fri, 17 Sep 1999 09:00:19 -0500

From: <owner-bpr@philologos.org>

September 16, 1999
17:28 GMT 18:28 UK

Small but deadly comets identified

BBC News Online
Full story at:
http://news.bbc.co.uk/hi/english/sci/tech/specials/sheffield_99/newsid
_449000/449554.stm

A "small" comet impact on Earth is the most likely extraterrestrial
object to kill millions of people and it could happen at any moment,
according to a British expert.

Dr Matt Genge, from London's Natural History Museum, has
investigated the damage a wide range of "small" meteors and comets
would have if they struck our planet.

He identifies comets between just 50 to 100 metres wide as the most
terrifyingly destructive, with massive heat and shock waves burning
people and crushing buildings.

Dr Genge explains that whilst meteors bigger than two kilometres
could wipe out humanity, these hits are expected only once every
million years or so.

But smaller ones could still lead to the deaths of tens of millions and
arrive much more frequently. These are therefore much more
dangerous, he said.

Dr Genge was explaining his ideas at the British Association's Festival
of Science in Sheffield, UK.

Shock wave

A 60-metre-wide comet exploded over Siberia in 1908 with 600 times
the energy of the bomb dropped on Hiroshima. It laid waste to a 40-km-
wide patch of forest, but, fortunately, the area was unpopulated.

However, comets of this size are expected to strike the Earth every 100
to 300 years.

If the 1908 comet had arrived just eight hours earlier, it would have
struck London, killing everything as Dr Genge described.

The comet, made of ice and dust, would hit the atmosphere at 58,000
km/h (36,000mph). As it plunged downwards, air friction would heat
the object into a fireball and start to fragment it. Sonic booms would
thunder from the sky, before the comet exploded with tremendous
force.

Dr Genge said: "You get a large shock wave and thermal flash. It's
almost exactly the same as a nuclear air burst.

"Let's say you're a very fast thinker. In the micro-seconds you have
left, the first thing is that everything would burst into flames,
including you.

"You'd be knocked off your feet by the shock wave and then dragged
back again towards the explosion as all the air rushes back in."

Danger signs

After the blast, London would be a wasteland of flattened, charred
buildings and blackened corpses.

Dr Genge looked at the physical properties of meteorites and comets
to identify the Siberian-type strike as the most dangerous.

Ironically, it is because the 50 to 100-metre-wide comets are so weak
that they are so dangerous. They break up into fragments which
explode just a few kilometres above the ground - "the optimum altitude
for maximum devastation", said Dr Genge.

Stone and metal meteors of similar size are much stronger and do not
break up and explode.

However, 100-metre-wide metal meteors will create a blast area of 60
km across compared to just two kilometres for a stone meteor of the
same size. The metal's higher density is to blame.

Dr Genge believes that this type of analysis will help to decide what
level of danger an Earth-bound object would pose and aid decisions
about what course of action to take.

The trajectory of most objects in the Solar System can be predicted for
hundreds of years, but there still some that come with little warning,
such as comet Hale-Bopp.

via: hblonde1@tampabay.rr.com