Re: (meteorobs) Re: Meteoroid Size
> Bob wrote:
> Well George I was also somewhat surprised that the figures are close but
> there it is in black and white on page 30 of the 95 edition of the IMO's
> visual handbook. For those who do not have the handbook the density figures
> listed for the Geminids was 4.2 g/cm3 and 3.4 g/cm3 for the Perseids. These
> figures were taken from Babadzhanov's 1994 results.
>Yes I see it. Seems kinda dense? Is there any conflict with table 1-1 where it
>shows the mass of a 0 magnitude eta aquarid meteor at 1 gram and a diameter of
>2 cm's? The table on page 30 shows the eta aquarids having a density around
The figures I've always seen in the literature for meteoroid densities were
(with the exception of the Geminids) always in the sub-gram/cm^3 range also,
George. One thing I noted was these studies were of brighter shower members.
Could this unexpectedly high figure for cometary showers be the result of a
relationship between particle size and density in cometary meteoroid streams?
In other words, are "normal" brighter meteors far more dense than "normal"
less bright ones for some reason? Thinking about the "dirty snowball" model,
it seems at least plausible to imagine that any particle large enough to be
a fireball might actually have been a more dense "rocky" particle embedded
in the comet nucleus... Jim, did those papers you mention mention or account
for any sort of sampling bias with respect to size?
BTW Bob, I understood from Petr that Phaethon (parent body of the Geminids)
probably CANNOT have been a comet once, since it is rotating so fast now.
But then again, if comets really turn out to be very dense, maybe that
changes the interpretation of Petr's results??