[meteorite-list] Multiple Impact and 73P(was..More Evidence Chicxulub..)

[MexicoDoug at aol.com]

Sterling W. writes:

<<  Keller-Harting get lots of press, but nobody
 is convinced by them but them...  >>

Hola Sterling,

That isn't entirely true.  Gerta and her many European and Mexican 
collaborators have done much superb chonostratigraphic detective work and have been 
quite influential and have at least 15 years of solid science they've built.  That 
the original theorists have every right to defend for their dramatic 
extinction scenario hypothesis is fine and healthy to a point, but the devil is hiding 
in the details, and Marcus Harding's work takes this to a new level by 
attempting a look further at morphology and chemistry like has not been done before. 
 That is a good thing and these are exactly the type of folks needed since 
the geological record is so...errr...fragmented in the critical scheme of 
evaluating the hypothesis of the Nobel Prize winning Hollywood Impact Theory.  This 
work is fresh research on a question that is so complicated that other 
researcher's won't touch since the possibility of successfully nailing it is slim 
after all of these 65.X million years.  The fact the the press and more 
importantly the scientists themselves seem to be vocally passionate about their 
hypotheses does not excuse the true inconclusivity of the evidence for the accepted 
theory which merits keeping the issue on the table for the mainstream.

Dr. Keller wisely sticks to her paleontological expertise, but if you have 
had an opportunity to discuss this with her you will know that her thinking 
regarding the killer asteroid scenario is quite refreshing and robust.  The idea 
that multiple impacts ocurred doesn't seem to far fetched, and we can basically 
thank them for introducing it as potentially more viable and consistent based 
on top-notch fieldwork, not just astronomical mullings.  If you want to dream 
up a nice scenario just look at the two dozen large pieces of Comet 
Shoemaker-Levy that pummelled Jupiter for over a week.  Of course, Jupiter has pretty 
high-test fishing line compared to Earth and can land these beasts on the first 
try.

So, let's have fun in about a month with some binoculars where you'll see two 
cometary fragments from Comet 73P Schwassmann-Wachmann 3 on May 12 and 14 
even from somewhat light polluted skies at nice, forgiving altitudes for backyard 
astronomers.  Component C, apparently the main mass, passes 0.08 AU from 
earth first (on a sky trajectory before the 11th of May entering Vulpecula the Fox 
between the base of the cross of Cygnus the Swan and the second front leg of 
Pegasus the Flying Horse, and then less than two days later, at only 0.066 AU 
just about leaving Vulpecula and entering Pegasus another huge mountain of 
component B will be whizzing by.  Some of these chunks are in the 500 meters to 1 
kilometer diameter range.  There are over a dozen killer chunks detected so 
far.  Some good food for thought while there's still food and thought 
available:)  Too bad NASA lost the CONTOUR spacecraft a month after it was launched in 
July 2002.  If the heliocentric booster maneuver hadn't been a failure, on 
June 18, Contour (That's COmet TOUR, not COmetS:)) would have made the most 
dramatic flyby of 73P than anything we have yet witnessed in our fortuitous 
livespans...

There'll be a basically moon out for 73P as it passes Earth most closely so 
unfortunately the binocular view won't be very astounding and may only catch 
the largest C fragment.  The best time to see the comet if you are serious is on 
May 7 or 8 at about 3:30 AM local time.  During this time the main mass of 
the comet will be visiting the small, bright parallalelogram in Lyra the Lyre.  
Just find Vega in Lyra, then the second brightest star in the constellation 
and follow the side of the parallelogram where the Ring nebula is.  The Comet 
will be brushing by it for some nice opportunities in moderate telescopes to bag 
the comet and nebula together...(and the nucleus will be visible in your 
binocular, though the Ring Nebula probably not unless you have some 30X100mm's)...

Clear Moonless Skies,.
Saludos, Doug