Department of Climate and Space Sciences and Engineering in the College of Engineering at the University of Michigan

CLaSP Seminar Series - Prof. Joseph Westlake

Date: September 20, 2018
Time: 3:30 pm - 5:00 pm
Location: CSRB Auditorium, room 2246

Our guest for this week's CLaSP Seminar Series will be CLaSP Adjunct Prof. Joseph Westlake, also of APL. Please join us! 

Title: "The Plasma Instrument for Magnetic Sounding (PIMS) Onboard the Europa Clipper Mission"

Abstract: The Europa Clipper mission is equipped with a sophisticated suite of 9 instruments to study Europa's interior and ocean, geology, chemistry, and habitability from a Jupiter orbiting spacecraft. This mission to Europa is tasked with characterizing Europa's subsurface ocean and assessing Europa's habitability. The magnetic sounding investigation exploits currents induced in Europa's interior by the moon's exposure to variable magnetic fields in the Jovian system to infer properties of Europa's subsurface ocean such as its depth, thickness, and conductivity. This technique was applied to Galileo observations and demonstrated that Europa indeed has a subsurface ocean. 

Complicating this investigation is the fact that Europa is embedded in a complex Jovian magnetospheric plasma, which rotates with the tilted planetary field and interacts dynamically with Europa's ionosphere affecting the magnetic induction signal. Plasma from Io's temporally varying torus diffuses outward and mixes with the charged particles in Europa's own torus producing highly variable plasma conditions at Europa. Thus, characterization of the ocean by magnetic sounding requires an accurate specification of how the plasma properties, specifically the mass density and flow velocity of the plasma change as it flows across Europa.
The PIMS (Plasma Instrument for Magnetic Sounding) measures the plasma surrounding Europa to characterize the magnetic fields generated by plasma currents. PIMS uses Faraday Cups to measure the plasma mass density and flow velocity. PIMS works in conjunction with the Interior Characterization of Europa using Magnetometry (ICEMAG) investigation to magnetically sound Europa's subsurface ocean. The measured plasma properties along with detailed physics-based modeling of the moon-magnetosphere interaction establish the contributions to the total magnetic field of plasma currents. Taking advantage of the differing spatial forms of fields from plasma and induction currents, an inversion scheme is able to markedly increase the accuracy with which the inductive field signature can be characterized to determine the ice shell thickness, ocean depth, and conductivity.
This talk will discuss the scientific impetus and expected scientific return from plasma and magnetic field measurements onboard the Europa Clipper mission as well as progress to date on the PIMS instrument.


 


Upcoming Events

September 20th
3:30 pm - 5:00 pm
CLaSP Seminar Series - Prof. Joseph Westlake
September 24th
5:30 pm - 7:30 pm
CLaSP Department Town Hall Meeting - All Students
September 28th
1:30 pm - 2:30 pm
CLaSP Seminar Series - Dr. Kristin Lewis
October 3rd
1:00 pm - 2:30 pm
Climate & Space Ice cream Social
More Events