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RE: (meteorobs) Perseids storms predicted for 2029 (and other wil d stuff)




Jure,

You are right that presently, for a close encounter to happen, an inward
perturbation (dip) from either Jupiter or Saturn will be 'needed', while the
meteoroids are approaching. 

Look at: http://www.saunalahti.fi/~fmbb/astro/perseids.htm

The comet itself was affected in that way by Jupiter (at the latest return)
and there are visible (in the figurre that shows the 1 to 4-rev trails till
2020) two other 'dips' caused by Jupiter an one caused by Saturn (around
2009).

(Note the vertical scale is as rE-rD (this is like Rob and David also have
given the 'miss-distance', in numeric form), meaning that positions up from
the 'zero'line' are actually inside the Earth orbit. Since then I have
changed my habit of making the graphics.) 

This makes an encouter to happen less likely than it woud be, if the more
smooth parts (of the trails) were at the Earth orbit 'level'. Since the
comet itself was perturbed (in this way) to go inside the Earth orbit in
1992, the situation may get more favorable for the next return of the parent
comet, but sorry I have not yet studied that far into future. I have made
the parent comet iontergrations well into future. I don't have those here in
my work, but recall that the situation (as judged from the comet q-value)
may look favorable. (..although we may not be ourselves then here on Earth
to take advantage of this :-) 

The other dip's that you can see in the figure, are too much (more than in
2004) inside the Earth orbit at the time of (in early August) the Perseids.
(The vertical lines in the figure are at the start of each year.)  I have
not found any other (as favorable or more) favorable encounter soon to come,
but I am not very certain that all trails have been inspected carefully
enough. (I think that they are to exclude other storms soon, but maybe some
other weaker outburtsts..) Continuing the one revolution trail that behaves
more regularly than the others might yield a year with the dip at the
correct position of the year. It is however expected that quite soon (after
or aven already at 2020) the one revolution trail will be about empty from
(meteoroids procucing) visual meteors. These are too distant (too big
original delta_a) from the comet in the one revolution trail. Depending
however on the actual amount of smaller meteoroids, the more 'distant
locations' in the trail MAY be densely occupied by smaller meteoroids that
could give rise to a telecopic outbuts (possible even strom?). These
hypothetical small particles are expected for the most part to get 'pushed
by solar radiation pressure' into these longer period orbits. Unfotunately
there is quite little data on these even with the Leonids. I expect that,
with the Leonids,  after 2006 and 2007, we will know more on the
distribution/amount of smaller (than  those giving visual meteors)
meteoroids.

Esko

>>>

Hi!

  While this may have been a typo on Daniel's side or a minsunderstanding,
he 
wrote:

9. that the Perseids will experience new strong outbursts from 2004 onwards
and 
will reach storm level from 2029 (which should read 2028) onwards

Do you expect further outbursts in 2005 and later and storms also in 2029
and 
later? As I recall the 2004 outburst would be caused by an orbital
preturbation 
of a section of the 1-rev (or was it 4-rev) trail and by the following year
the 
miss distance would again increase beyond the possibility of an outburst?

Clear skies!

Jure A.

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