(meteorobs) 1972 Draconids [was 2005 Draconids]

[Skywayinc at aol.com]

In a message dated 1/25/2005 11:28:57 A.M. Eastern Standard Time,  
mjc at star.rl.ac.uk writes:

I'm  wondering why _at the time_ there was an expectation
of at least abnormal  activity.  There was the closeness of the orbits
crossing only a  couple of months after the comet. 


I don't have the exact figures at this moment (I am at work right now), but  
I certainly remember the excitement that surrounded the possibility of a  
Giacobinid/Draconid outburst in 1972.  If memory serves me correct,  
21P/Giacobini-Zinner was perturbed by Jupiter in 1969 that brought the comet's  orbit very 
near to the Earth for its 1972 apparition.  The Earth was going  to follow the 
comet to the nodal crossing point by only about 58 days . . .  which was 
roughly midway between the 1933 and 1946 storms. 
 
Unfortunately, hardly anything was seen.  One explanation that was  floated 
at the time was that fresh cometary material did not have a chance  to 
sufficiently spread out behind 21P after its orbit was changed in  1969.  As we now 
know, the old "analog" method of anticipating a meteor  outburst by looking at 
the parent (comet) body's position relative to Earth is  not always reliable!  
Tracking the actual dust trails ejected from the  comet serves the purpose 
much better.
 
The analog method would suggest an Draconid outburst in 2018, since the  
distance between the comet orbit and the Earth is roughly midway between  the 
values of 1933 and 1985 and the Earth will be following the  comet to the node by 
only 22 days.  However, it appears that using the dust  trail method, an 
outburst does not appear likely as it appears that  Earth will not encounter any 
recently ejected trails.
 
-- joe rao