[meteorite-list] EPOXI images of Comet Hartley 2

From: Meteorites USA <eric_at_meteoritecentral.com>
Date: Thu, 04 Nov 2010 10:32:56 -0700
Message-ID: <4CD2EE48.6020102_at_meteoritesusa.com>

My mistake on the method of propulsion... Thanks for clearing that up
for me Chris.. ;)

On 11/4/2010 10:03 AM, Chris Peterson wrote:
> Eric-
>
> The Yarkovsky effect does not work by vaporizing material. It is
> related to the momentum of photons.
>
> In the case of outgassing, the momentum is very low compared with the
> momentum of the nucleus, so the effect on the orbit is small as well.
> The Yarkovsky effect is also quite small on a body the size of
> Hartley. I think Yarkovsky dominates because it is a continuous
> process over the entire orbit, whereas outgassing only occurs during
> the time the nucleus is near the Sun. But in reality, both effects, as
> well as others (like gravitational perturbation) produce an orbit that
> can't be accurately predicted too far into the future. It is important
> to regularly recalculate orbital elements for bodies like this if very
> precise position information is required. I noticed during the flyby
> this morning that there seemed to be a miscalculated close passage
> time, which was corrected by a few minutes when the comet's orbit was
> recalculated.
>
> Chris
>
> *****************************************
> Chris L Peterson
> Cloudbait Observatory
> http://www.cloudbait.com
>
>
> ----- Original Message ----- From: "Meteorites USA"
> <eric at meteoritesusa.com>
> To: <meteorite-list at meteoritecentral.com>
> Sent: Thursday, November 04, 2010 10:35 AM
> Subject: Re: [meteorite-list] EPOXI images of Comet Hartley 2
>
>
>> Hi Gary, Your explanation of the outgassing of comets and Count
>> Deiro's question, made me think of one of the proposed ways of
>> deflecting asteroids which uses the Yarkovsky effect to focus the
>> suns energy on the outer surface of the asteroid thereby vaporizing
>> material and causing a propulsive force to nudge the asteroid into a
>> new orbit.
>>
>> So, if the Yarkovsky effect will work on asteroids, what's the
>> difference between that, and Comet Hartley 2's outgassing on the
>> orbit of the body? Is the force from the outgassing that much less
>> than what the Yarkovsky effect could produce?
>>
>> Regards,
>> Eric
>
> ______________________________________________
> Visit the Archives at
> http://www.meteoritecentral.com/mailing-list-archives.html
> Meteorite-list mailing list
> Meteorite-list at meteoritecentral.com
> http://six.pairlist.net/mailman/listinfo/meteorite-list
>
Received on Thu 04 Nov 2010 01:32:56 PM PDT