Re: Comets returning to perihelion before expected?

On Thu, 21 Sep 2006 16:42:18 -0400, "nitelite"
<andrew_33143@xxxxxxxxxxxxxxxx> wrote:

Hello, Everybody:

I'm interested in gravitational anomalies, and thus I found the paper "Is
the physics within the Solar system really understood?" by Laemmerzahl,
Preuss and Dittus (2006) most interesting as well (arXiv:gr-qc/0604052
v1).

I have a question about a point raised in Section 8.2, page 14 of the
arXiv.org printing. In that paragraph, the authors write: "Comets usually
come back a few days before they are expected .... The delay usually is
assigned to the outgassing of these objects .... also leads to the effect
that comets come back a few days earlier."

They say that comets return earlier than expected, but they also suggest
(by using the word "delay" twice) that they actually come back later than
expected. Can anyone here clarify this for me. Do comets come back to
perihelion earlier or later, or is it unpredictable?

I've contacted the authors of this paper for clarification, but they have
not yet replied. Can anyone here help me out in the interim?

I've read Page, Dixon and Wallin's paper "Can minor planets be used to
assess gravity in the outer solar system?" (arXiv:astro-ph/0504367), which
the authors cite [44] in which they say in Section 2.1, page 6, that
individual comets sometimes return earlier and sometimes later, due
primarily to outgassing and other forces discussed by Marsden, Sekanina &
Yeomans (1973). They write that these are statistical forces that apply
over many returns and cannot be used to predict the time of a comet's
perihelion return on any single orbit.

I'd be very grateful if anyone could direct me to sources that confirm
that specific (or all) comets return "early." I would like to see data on
that subject as I am doing some research on precession.

Many thanks!

Andrew

.

Relevant Pages

  • Comets returning to perihelion before expected?
    ... the authors write: "Comets usually ... Can anyone here clarify this for me. ... They write that these are statistical forces that apply ... perihelion return on any single orbit. ...
    (sci.geo.satellite-nav)
  • Comets at perihelion before expected?
    ... the authors write: "Comets usually ... Can anyone here clarify this for me. ... They write that these are statistical forces that apply ... perihelion return on any single orbit. ...
    (sci.astro)
  • Re: Comets returning to perihelion before expected?
    ... the authors write: "Comets usually ... Can anyone here clarify this for me. ... They write that these are statistical forces that apply ... perihelion return on any single orbit. ...
    (sci.geo.satellite-nav)
  • Re: Comets at perihelion before expected?
    ... the authors write: "Comets usually ... Let's make the assumption that comet perihelion is ... closer to the sun than Earth's orbit (obviously not true for Pluto, ... There is no preferred orbit that all comets must take, ...
    (sci.astro)