🚀 go-pugleaf

On Fri, 8 Jan 1993 02:47:53 GMT T.Ryan and D.Moore, Astronomy Ireland,
P.O.Box 2888, Dublin 1, Ireland wrote the following.

>We are looking for information to help get some idea of what to expect with
>regard to the Perseid meteor storm predicted for August 1993. We presume that
>the comet's return to perihelion in 1862 (what date was perihelion?) should
>have caused storm levels also, particularly given its close approach of 32
>million miles, but no one seems to have seen anything. In his 1988 book
"Meteor
>Showers", Gary Kronk, only refers to good rates (up to 215/hour, not really
>storm rates) in 1861 and 1863 (no rates are given for 1862).

The comet passed perihelion on August 23, 1862. There actually was activity
reported on August 10, 1862 by the Japanese. They claimed, "Stars fell like
a shower at midnight." Some astronomers have categorized this observation as
a "storm," but no meaningful figures can be derived.

>Was there a Full Moon on Aug. 9 1862 i.e. was moonlight the problem?

Yes. Full moon occurred on August 9, 1862, at 21:23 UT.

>Did the comet and Earth's orbits not cross as closely as they do now?

The orbit of the comet has changed surprisingly little during the last 2000
years according to the computations furnished by Brian G. Marsden which
link the comet to Chinese comets appearing in 188 and -68. Meteors showers
would still be expected.

>Could it be that as the storm only lasts about 1 hour, an unpopulated part of
>the dark side of the Earth was facing into the radiant (or poor weather)?

Bingo! The nature of the "storm" would be an extremely narrow spike. If it
occurs over a nonpopulated area or an area experiencing cloudy skies, the
"storm" would easily be missed.


I have done much more detailed studies of the Perseids, especially of the
possible storms reported by the Chinese and Japanese during the last 2000
years which usually occurred decades before or after the comet reached
its perihelion, but the information above should directly answer most of
your questions.

Sincerely,
Gary W. Kronk