[ExI] first step as principle investigator
David C. Harris
dharris234 at mindspring.com
Sun Mar 9 09:17:44 UTC 2008
Congratulations, Amara! I'm so glad your powerful talents are being
recognized with financial support. Yay!
- David Harris, Palo Alto
Amara Graps wrote:
> Hi Extropes,
>
> The nine months I spent last year writing government grant proposals
> wasn't for nothing, this morning I learned that my last NASA proposal
> will be funded (a small project: 4 months per year for two years). This
> is my first research proposal where I'm the 'principle investigator'.
>
> This means that I'm part-way on the road now to being a self-funded
> planetary astronomer. After making my large move to a 2 year salary
> position, this funding source isn't necessary for my life now, but
> it does give me a buffer while I gain more practice writing proposals
> and submit several more like this one, so that I can be completely
> self-funded when my current SwRI position ends.
>
> I've pasted the topic below.
>
> Amara
>
> -------------------------------------------------------------------
> The Development of the Saturnian Dust Streams
>
> Interplanetary dust streams are highly collimated, high-velocity
> submicron particles that can extend over several A.U. They arise from
> the coupling of planetary magnetic fields and sources of dust production
> in circumplanetary environments. The first streams were detected
> emanating from the Jupiter system by the Ulysses mission in 1992. They
> were detected continually inside of Jupiter's magnetosphere and dozens
> of times in interplanetary space by the Ulysses, Galileo and Cassini
> spacecraft. Dust streams emanating from the Saturn system were detected
> by the Cassini Cosmic Dust Analyser (CDA) in 2004, at a distance of half
> an A.U., and they continue to be detected as Cassini orbits Saturn.
> Graps \cite{Graps:2000a}\ identified Io as the dominant source of the
> Jovian dust stream particles, but the source or sources of Saturnian
> dust stream particles is unknown. Possibilities to be investigated
> include (but are not limited to) Enceladus geysers, fragmented E~ring
> particles, and collisional fragments from the Main rings. CDA includes a
> time-of-flight mass spectrometer, providing compositional information
> not available from Galileo and Ulysses, which will provide new insights
> and constraints to address particle source issues.
>
> The coupling of the planetary magnetic fields and their sources of dust
> production has been found to have large physical consequences in the
> Jovian and Saturnian magnetospheres. Given the prodigious quantity of
> dust produced, Graps \cite{Graps:2006a}\ and others \cite{Wahl:2006}\
> have indicated that dust production in both the Jupiter and Saturn
> systems may be large enough that conditions would exist for dusty
> plasmas, which lead to collective behavior of the dust particles. This
> can be a factor in the formation of dust streams. This coupling of the
> planetary magnetic fields and their sources of dust production also
> leaves its imprint on the dust streams' signature in frequency space,
> allowing one to study the source of the dust streams.
>
> Not all dust destined to escape in streams from a circumplanetary region
> escape immediately. The time for a particle to charge up and accelerate
> gives a residential lifetime to the smallest particles in the vicinity
> of their host. Such a temporary residence of a population of tiny
> particles can be a hazard to objects in the vicinity (instruments,
> people), as well as a source dust population for other physical
> processes (e.g., impact related). Once these particles escape into
> streams into interplanetary space, they have been correlated with the
> leading edges of high-speed solar wind streams (called corotating
> interaction regions or CIRs) and the Sun's coronal mass ejections
> (CMEs), adding further to the complexity of their dynamical evolution.
>
> We propose to quantify the conditions under which collimated dust
> streams form and evolve in the Saturn system to reproduce the CDA
> observations and compare it to the generation of dust streams in the
> Jupiter system. Objectives include:
>
> \begin{itemize}
> \item Determine the sources of dust stream particles from the Saturn
> system with frequency analysis and modeling and compare them to those of
> Jovian dust stream particles. Can dust production required for streams
> be generalized to other solar system bodies (e.g., geysers on Triton)?
> \item Model the contribution of both planetary and solar magnetic fields
> to the formation and evolution of dust streams.
> \item Determine the time evolutionary state of the spatial density and
> particle size distribution of stream particles within the Saturn
> magnetosphere.
> \item Determine the locations and (plasma, dust) parameters of dusty
> plasma conditions and their impact in the formation of dust streams.
> \end{itemize}
>
> The analysis of Cassini datasets with a focus on the Saturnian dust
> streams is valuable for understanding the dust streams' source, for
> understanding the dynamical development of the streams, and for
> predicting where we might detect streams elsewhere, thereby realizing
> the objective of the Cassini Data Analysis Program (CDAP) of enhancing
> the scientific return of the Cassini mission. This project supports
> NASA's Strategic Goals by Strategic Sub-goal 3C, it contributes to the
> NASA Science Outcomes 3B.1, as well as Science Outcomes 3B.3. As cosmic
> dust is both a building block and by-product of solar system
> evolutionary processes, this project also contributes to NASA's Science
> Outcomes: 3C.1.
>
> -------------------------------------------------------------------
>
>
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