[meteorite-list] Detectability

From: E.P. Grondine <epgrondine_at_meteoritecentral.com>
Date: Mon, 7 Sep 2009 16:25:33 -0700 (PDT)
Message-ID: <928976.16169.qm_at_web36901.mail.mud.yahoo.com>

Thanks once again Richard -

I hadn't thought of that, but then I don't think of many things now days. I assumed that list concerned simply observational data, and was quite expensive to join.

Looking up 2007 DN41, it does not appear to have been sufficiently dead, and was only detected once outbound after it had been through perihelion, a little late for comparative purposes.

Ed

--- On Mon, 9/7/09, Richard Kowalski <damoclid at yahoo.com> wrote:

> From: Richard Kowalski <damoclid at yahoo.com>
> Subject: Re: Detectability
> To: "E.P. Grondine" <epgrondine at yahoo.com>
> Cc: meteorite-list at meteoritecentral.com
> Date: Monday, September 7, 2009, 5:50 PM
> We're due to start the 2009-2010
> observing season tomorrow and I'm back on a night schedule
> so am a little sleepy and ready for a nap, but doing a quick
> check on an object the size you're looking for, assuming an
> albedo of 5%. I come up with 2007 DN41 as a candidate. I
> don't know the actual albedo, but you can do a more detailed
> search when you have the opportunity.
>
> Running the ephemerides back from discovery, (17.9V) we
> could have discovered it as much as three weeks earlier
> under perfect conditions when it was about 12 million
> kilometers (7.5 million miles) away.
>
> Your questions might be better answered if you posted on
> MPML. There are many more experts on the subject there who
> have already studied the problem in detail and can answer
> with more authority.
>
>
> --
> Richard Kowalski
> http://fullmoonphotography.net
> IMCA #1081
>
>
> --- On Mon, 9/7/09, E.P. Grondine <epgrondine at yahoo.com>
> wrote:
>
> > From: E.P. Grondine <epgrondine at yahoo.com>
> > Subject: Re: Detectability
> > To: "Richard Kowalski" <damoclid at yahoo.com>
> > Cc: meteorite-list at meteoritecentral.com
> > Date: Monday, September 7, 2009, 3:13 PM
> > Richard -
> >
> > Thanks much again. Great work with TC3.
> >
> > I am assuming that TC3 also had an orbit that created
> a
> > detectable arc with your image analysis algorithm.
> Would a
> > cometessimal directly inbound on a long period or
> short
> > period orbit do so?
> >
> > The problem is to take that 19.0V and turn it into a
> > detection limit estimate for an inbound 30 meter
> > carbonaceous chondrite, and further to turn that limit
> into
> > an estimate of warning time. Sadly, those maths are
> well
> > beyond me now.
> >
> > Ed
> >
> >
> > --- On Mon, 9/7/09, Richard Kowalski <damoclid at yahoo.com>
> > wrote:
> >
> > > From: Richard Kowalski <damoclid at yahoo.com>
> > > Subject: Re: Detectability
> > > To: "E.P. Grondine" <epgrondine at yahoo.com>
> > > Cc: meteorite-list at meteoritecentral.com
> > > Date: Monday, September 7, 2009, 5:03 PM
> > > Ed,
> > >
> > > checking my observing report from 6 October,
> 2008,
> > the
> > > night of discovery, the conditions were far from
> > perfect and
> > > the seeing wasn't that great. I reported it as
> 2.3
> > > arcseconds full width half max for the night.
> > >
> > > The night before was cloudy and I didn't head up
> to
> > the
> > > observatory. The night of impact the seeing was
> only
> > > slightly better, but highly variable and both of
> > these
> > > nights were windy. Perfect nights have
> sub-arcsecond
> > seeing
> > > and our fwhm (1 arcsec pixels) is <1.8
> > >
> > > With the 1.5-m we can reach 19.0V with good SNR
> using
> > a
> > > 5-second exposure AT Nautical Twilight.
> > >
> > > --
> > > Richard Kowalski
> > > http://fullmoonphotography.net
> > > IMCA #1081
> > >
> > >
> > > --- On Mon, 9/7/09, E.P. Grondine <epgrondine at yahoo.com>
> > > wrote:
> > >
> > > > From: E.P. Grondine <epgrondine at yahoo.com>
> > > > Subject: Detectability
> > > > To: damoclid at yahoo.com
> > > > Cc: meteorite-list at meteoritecentral.com
> > > > Date: Monday, September 7, 2009, 2:44 PM
> > > > Hi Richard -
> > > >
> > > > Thanks for the information, and
> congratulations
> > on
> > > TC3.
> > > >
> > > > I make that 320,000 miles something like 2
> hours
> > if it
> > > had
> > > > of been on a direct intercept orbit. I am
> > assuming you
> > > had
> > > > nearly perfect sky conditions as well at
> your
> > > observatory.
> > > >
> > > > I think this one is going to turn into
> photons in
> > a
> > > bucket
> > > > and sky conditions.
> > > >
> > > > The items of interest are cometessimals,
> the
> > smallest
> > > > around 30 meters with 5 kilton impact force
> by
> > my
> > > current
> > > > estimate, with 2 joined cometissimals around
> 60
> > meters
> > > and
> > > > 15 megatons of impact force. (But I have
> been
> > wrong
> > > before,
> > > > and reserve the right to be wrong in the
> > future.)
> > > >
> > > > No one in NASA seems to know what happened
> to
> > the
> > > CAPS
> > > > analysis. It is probably sitting on a shelf
> > somewhere
> > > with
> > > > the Apollo 11 Moon walk slowscan tapes.
> > > >
> > > > E.P. Grondine
> > > > Man and Impact in the Americas
> > > >
> > > >
> > > >
> > > >
> > >
> > >
> > >
> > >
> >
> >
> >
> >
>
>
>
>


      
Received on Mon 07 Sep 2009 07:25:33 PM PDT