[Baps] BU Seminar - Don Mitchell (APL) Saturn's magnetosphere

[Paul Withers]

Our seminar series is about to start. For the full list, see:
http://www.bu.edu/csp/edoutreach/seminar/

Planetary speakers this semester include:
Heather Knutson, Jason Soderblom, Melissa McGrath, Ralph McNutt

Paul


-------- Original Message --------
Subject: 	[Csp_seminar] THURSDAY: Don Mitchell (JHU-Applied Physics Lab)
Space Physics Seminar
Date: 	Tue, 4 Sep 2012 18:56:35 +0000
From: 	Savoie, Alyson L <asavoie at bu.edu>
To: 	announce at skynet.bu.edu <announce at skynet.bu.edu>,
csp_seminar at bu-ast.bu.edu <csp_seminar at bu-ast.bu.edu>, iar at skynet.bu.edu
<iar at skynet.bu.edu>



Space physics seminar

Donald Mitchell

Johns Hopkins University, Applied Physics Laboratory

*“*Imaging Saturn’s Magnetosphere—Solar Wind-Driven and Rotational
Dynamics on the Large Scale*”*

*Thursday, September 6, 2012*

*Refreshments at 3:30pm in CAS 500*

*Talk begins at 4:00pm in CAS 502*

Abstract:

The Outer Planet Gas Giants, Jupiter and Saturn, both rotate faster than
Earth (between 10 and 11 hour periods), and have strong internal
magnetic fields that stand off the solar wind, and populated with
plasmas derived from their moons. At Saturn, the Cassini mission has
been shedding light on the behavior of this vast rotating magnetosphere.
Because the magnetosphere is so large (roughly 20 times the scale of
Earth's magnetosphere) and we have only one spacecraft (unlike Earth,
where we have multiple probes distributed throughout the system), the
understanding of in-situ plasma data is complicated by not knowing what
is happening remote from Cassini: is a change in particle intensity (or
plasma density or temperature) a temporal change, or a consequence of
crossing a spatial boundary? What is happening elsewhere in the
magnetosphere? Some of this mystery is resolved by the images provided
by the Cassini Magnetospheric Imaging Instrument's Ion and Neutral
Camera--MIMI/INCA. This energetic neutral atom (ENA) imager takes global
images of the hot plasma distribution in Saturn's magnetosphere by
measuring the trajectories and energies of energetic atoms created as
magnetically trapped, energetic ions charge exchange with the cold
neutral gas (water vapor) that suffuses much of the magnetosphere. The
resulting ENAs no longer experience the magnetic forces that confined
them as ions, and much like photons radiate away from their source
regions. By constructing movies of this emission at a fraction of an
hour time resolution we can reveal rotational and solar wind compression
driven magnetospheric dynamics. These images also provide a means to
connect magnetospheric dynamics with simultaneously imaged Saturn
auroral features."

----

Alyson Savoie

Fiscal Administrator

Boston University

Center for Space Physics

Institute for Astrophysical Research

725 Commonwealth Avenue, Room 506

Boston, Massachusetts 02215

Tel: 617-358-0603

Fax:617-353-6463