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Comet Encke and Taurid Meteorites

1999 Beta Taurid Meteorites:

7 July 1999 -Giant meteor explodes over New Zealand

According to an 8 July 1999 article in the London Telegraph by Paul Chapman,

"... A SEARCH began yesterday for the remains of a large meteor that exploded over New Zealand's North Island with enough force to shake buildings, leaving a plume of blue smoke

(photo from the New Zealand Herald, according to which "... The Carter Observatory in Wellington received reports of the meteorite about 4.15 pm. It was picked up by aircraft and radar. ...".)

that covered hundreds of square miles. Falling debris from the meteor, which eyewitnesses said was as bright as the sun, was blamed for starting a forest fire near Napier, on the east coast. The spectacular explosion was seen by people on both sides of the North Island and from as far north as Auckland to Christchurch in the South Island. Witnesses said the fireball had a long, fiery tail. Airline pilots reported sightings and the meteor was picked up on radar by air-traffic controllers. Rodney Austin, information officer for the New Zealand Astronomical Society, said the meteor could have been as large as a railway locomotive. One scientist said it could prove difficult to find in New Zealand's rugged and sparsely populated landscape. ...".


1998 Beta Taurid Meteorites:

20 June 1998 - According to the 3 July 1998 edition of Sky and Telescope's Weekly News Bulletin, a meteorite fell about 100 kilometers from Tashauz, Turkmenistan. The daylight fall was preceded by a dazzling orange bolide that left a train of black smoke as it moved northeast across the sky. The projectile broke into at least three pieces before impact, and the largest fragment created a small crater about 6 meters wide and 4 deep. At its bottom a recovery team found a cone-shaped stony iron meteorite weighing between 300 and 500 kilograms.

13 June 1998 - Meteorites fell in Nashville, Tennessee, and in Portales, New Mexico, according to Sky and Telescope's Weekly News Bulletin of 19 June 1998.



In 1940 Whipple discovered that the Taurid meteors 
were fragments of Comet Encke, 
with period 3.3 years, perihelion 0.34 AU, and aphelion 4.1 AU, 
and that the differences in the orbits of the meteors and Comet Encke 
looked like the result of 14,000 years of perturbations by Jupiter.  
In 1950, Whipple and Hamid discovered that 
the orbits of four Taurid meteors coincided 
with the orbit of Comet Encke as of 4700 years ago, 
and that, as of 1500 years ago, 
the orbits of three other Taurid meteors coincided with each other 
but not with the orbit of Comet Encke.  
They concluded that the latter three Taurids were formed 
by a breakup 1500 years ago of a fragment that had in turn 
broken off from Comet Encke much earlier.  

According to the web page of Gary Kronk, Whipple's 1940 paper discussed more than the Taurids and their link to comet Encke. Whipple said the stream's apparent spread of 0.2 AU meant Mercury, Venus and Mars were also likely to encounter it.


Clube says that fragments of Comet Encke 
make up the Taurid meteor stream, 
which peaks around 30 June in daylight hours 
but is visible in the night skies of November, 
and that 
the Earth passes through each dense part of this belt 
of debris every 3000 years.  

The daylight June Taurids, known as the Beta Taurids, are active during June 5 to July 18 with a relatively flat maximum centered on June 29, according to the web page of Gary Kronk.

The nighttime Taurids fall into two streams, the Northern (active from October 12 to December 2 with maximum during November 4-7) and Southern (active from September 17 to November 27 with maximum during October 30 to November 7. The Northern Taurids have orbits that are very similar to the daylight Beta Taurids. (See the web page of Gary Kronk.)

Given the incompleteness and uncertainties of observations, 
and uncertainties of calculations, 
and the rough estimate nature of the scales of time, etc., 
that I use on my WWW pages, I take 
the size of the parent comet to be roughly 100 km, 
roughly the size of Hale-Bopp or Sarabat, 
the initial breakup of Comet Encke to be about 12,000 years ago, 
roughly coincident with the Vela X Supernova 
and with the end of the Ice Age, 
secondary breakups to have occurred about 4,500 years ago 
and about 1,500 years ago.  
Observers on Earth see the Taurids as appearing to come 
from a radiant point in Taurus near the Pleiades.  
12,000 years ago, when the Ice Age ended, 
they might have seen a spectacular cometary display near the Pleiades, 
as the Earth could have encountered a lot of comet dust 
that might have affected its climate, 
all with the Vela X supernova appearing in the south. 
In his book Rogue Asteroids and Doomsday Comets (John Wiley, 1995),
Duncan Steel says a majority view of the consequences to Earth 
of major comet/meteor impact is that:  
     1 - for weeks, radiated heat (and impact heat) would heat up 
         the Earth, causing global fires, which in turn would 
         put a lot of soot and CO2 into the atmosphere; 
     2 - for years, atmospheric soot, dust, and pulverized rock would 
         reflect sunlight, causing a Cosmic Winter. 
     3 - for thousands of years, atmospheric CO2 would heat the Earth 
         through the greenhouse effect.  
9,000 years ago, after one 3,000 year period, 
and after 3000 years of greenhouse effect, 
the Earth entered a 3,000 year period of good climate.   
Then there might have been another encounter.  
6,000 years ago, when the good climate ended, 
perhaps due to a severe encounter with the 3000 year periodicity. 
There may have been a thousand years or so of greenhouse effect 
before the Earth's climate stabilized 
at the beginning of recorded human history about 5,000 years ago.  
3,000 years ago, when  the Iron Age began, 
the Zhou defeated the Shang in China, 
the short-lived monotheistic reign of Akhenaton ended in Egypt, 
and Moses led the Israelites out of Egypt,
the Chinese recorded that a comet (perhaps this comet) appeared.  
The Tunguska Impact of 30 June 1908 
may have been due to an Encke fragment associated with 
the Beta Taurid meteors. 
Now Comet Hale-Bopp is appearing, 
with a 3,000 year period (give or take 1,000 years or so).  
For more discussion of possible historical references to 
the fragments of Comet Encke, see the WWW pages 
of ABOB's Page.  


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