🚀 go-pugleaf

nickh@CS.CMU.EDU (Nick Haines) writes:

  [re: a post in article <STEINLY.92Oct27103531@topaz.ucsc.edu> 
   by steinly@topaz.ucsc.edu (Steinn Sigurdsson)]

>I keep reading this, and have a couple of questions to ask:

>1. S-T crosses Earth orbit twice every 120 years. The risk of
        ^^^^^^^ ^^^^^ ^^^^^ ^^^^^
This business about P/S-T crossing Earth's orbit twice each time around
has appeared in at least one other post.  It is not clear whether Nick
Haines is talking about the orbital plane or the orbital path.

Obviously P/S-T crosses Earth's ORBITAL PLANE twice, but that does not
imply that it crosses the ORBITAL PATH twice.  My understanding is
that the Perseids are the only meteor stream known to be associated
with this comet.  Earth passes through this stream each August.
Therefore, the comet crosses the orbital path of earth only once.  If
P/S-T crossed earth's orbit twice during its orbit as stated above,
then the Perseids would be a biannual event, which it is not.

Curt Roelle -- roelle@sigi.jhuapl.edu