The Europa Plasma Environment Tristan Weber LASP Fran Bagenal, - PowerPoint PPT Presentation

The Europa Plasma Environment Tristan Weber – LASP Fran Bagenal, Robert Wilson, Vincent Dols Friday, August 9, 2013

Europa Overview  Our interest in Europa  Our current understanding  Success/Limitations of our data  Refinement/Compilation of the data  Future improvements for the study of Europa http://photojournal.jpl.nasa.gov/catalog/PIA00502 Friday, August 9, 2013

Interest in Europa  Europa is “the first step in understanding the potential of the outer solar system as an abode for life” (Space Studies Board 2011, p.1)  Enough energy and water to sustain life Friday, August 9, 2013

Our Current Set of Data Variety of sources Ground Based Voyager Galileo 1. http://solarsystem.nasa.gov/galileo 2. http://www.cfa.harvard.edu/sma/ 3. http://voyager.jpl.nasa.gov/ Friday, August 9, 2013

Galileo -Failed Antenna Deployment -Lack of data resolution -Large range of trajectories -Wide spread of data if we could analyze it Friday, August 9, 2013

What We Know So Far Water Oceans Ice on surface shown from ground-based observations -Changing Magnetic Field Induces Currents -Seen by Galileo Hard to separate from Ionosphere Friday, August 9, 2013

What We Know So Far Water Oceans Ice on surface shown from ground-based observations -Changing Magnetic Field Induces Currents -Seen by Galileo Hard to separate from Ionosphere Friday, August 9, 2013

What We Know So Far Water Oceans Ice on surface shown from ground-based observations -Changing Magnetic Field Induces Currents -Seen by Galileo Hard to separate from Ionosphere Friday, August 9, 2013

What We Know So Far Water Oceans Ice on surface shown from ground-based observations -Changing Magnetic Field Induces Currents -Seen by Galileo Hard to separate from Ionosphere Friday, August 9, 2013

What We Know So Far Alfvén Wings Europa’s Footprint Friday, August 9, 2013

What We Know So Far Sputtered Atmosphere -Radiolysis embeds incoming particles and ejects others -Oxygen Atmosphere -Sulfur Deposits Friday, August 9, 2013

What We Know So Far Sputtered Atmosphere -Radiolysis embeds incoming particles and ejects others -Oxygen Atmosphere -Sulfur Deposits -Mostly Observed through Spectroscopy -Direct data has issues… Friday, August 9, 2013

Modeling  Working on a simulation with Vincent Dols  Magnetic Field Modeling  Data from NASA PDS Friday, August 9, 2013

Modeling  Working on a simulation with Vincent Dols  Magnetic Field Modeling  Data from NASA PDS E04 Flyby - 1996 Friday, August 9, 2013

Modeling ()*+,*- (4*+,*- '# &'# &## # ()*.231 (4*.231 '# ! '# # ! &## ! '# ! ! ! " # " ! $ % ! ! ! " # " ! $ % -*./01 -*./01 (5*+,*- (676*+,*- &'# "## &## &'# (676*.231 (5*.231 '# &## # '# ! '# # ! ! ! " # " ! $ % ! ! ! " # " ! $ % -*./01 -*./01 E04 Flyby - 1996 Friday, August 9, 2013

Modeling ()*+,*- (4*+,*- &## ! &"# ! &!# '# ! &$# ()*.231 (4*.231 # ! &%# ! '# ! "## ! &## ! ""# ! ! ! " # " ! $ % ! ! ! " # " ! $ % -*./01 -*./01 (7*+,*- (9:9*+,*- ! 56# !8# ! 56' !$# ! !## (9:9*.231 !'# (7*.231 ! !#' !!# ! !&# !5# ! !&' ! !"# !"# ! ! ! " # " ! $ % ! ! ! " # " ! $ % -*./01 -*./01 E11 Flyby - 1997 Friday, August 9, 2013

Modeling ()*+,*- (5*+,*- !# 4# !# '# '# "# ()*.231 (5*.231 "# &# &# # # ! &# ! &# ! "# ! "# ! ! ! " # " ! $ % ! ! ! " # " ! $ % -*./01 -*./01 (6*+,*- (787*+,*- !# 4# '# !# "# (787*.231 '# (6*.231 &# "# # &# ! &# # ! ! ! " # " ! $ % ! ! ! " # " ! $ % -*./01 -*./01 E11 Flyby - 1997 Friday, August 9, 2013

Modeling  Magnetic Field Modeling has been fairly successful  See Effects of Induced Currents and Alfvén Wings Kivelson et al. (1997)  E04 Flyby - 1996 Friday, August 9, 2013

Modeling the Plasma Properties  Want to compare model to direct plasma data.  Obtained plasma parameters with Rob Wilson’s fitting routine Friday, August 9, 2013

Modeling the Plasma Properties  Want to compare model to direct plasma data.  Obtained plasma parameters with Rob Wilson’s fitting routine %## ' 45.*67*8 9/3:;<0*8 $"# $## ,*-./01'(23 ! %+ !"# !## "# # ' ! !" ! !# ! " # " !# !" &'()*+ Friday, August 9, 2013

Modeling the Plasma Properties  Want to compare model to direct plasma data.  Obtained plasma parameters with Rob Wilson’s fitting routine %## ' 45.*67*8 9/3:;<0*8 $"# ? $## ,*-./01'(23 ! %+ !"# !## "# # ' ! !" ! !# ! " # " !# !" &'()*+ Friday, August 9, 2013

Problems with the PLS data  Fitting routine originally designed for full magnetosphere. Friday, August 9, 2013

Problems with the PLS data  Fitting routine originally designed for full magnetosphere. At moon encounters, the plasma might be changing too quickly to find a fit "## ( 456+07+8 &"# &## %"# -+./+01230+ %## $"# $## !"# !## "# ( ! !" ! !# ! " # " !# !" '()*+, Friday, August 9, 2013

A Possible Remedy  If the issue is over-averaging, edit the fitting to only run each spin individually  Danger of not having enough appreciable detections. Friday, August 9, 2013

A Possible Remedy Obs. Data Background Sim. Data +23.96:1.71 m:q 3 3 10 10 Counts/Accum. Counts/Accum. 2 2 Anode 1 Anode 2 10 10 1 1 10 10 0 0 10 10 3 3 10 10 Counts/Accum. Counts/Accum. 2 2 Anode 3 10 10 Anode 4 1 1 10 10 0 0 10 10 3 3 10 10 Counts/Accum. Counts/Accum. 2 2 Anode 5 10 10 Anode 6 1 1 10 10 0 0 10 10 52 104 156 208 260 312 364 416 3 Record # 10 Counts/Accum. 2 Anode 7 10 1 10 0 10 0 52 104 156 208 260 312 364 416 Record # DE run 1, Iter. = 1, Cost = 4.00001e+06 Friday, August 9, 2013

A Possible Remedy Obs. Data Background Sim. Data +23.96:1.71 m:q 3 3 10 10 Counts/Accum. Counts/Accum. 2 2 Anode 1 Anode 2 10 10 1 1 10 10 0 0 10 10 3 3 10 10 Counts/Accum. Counts/Accum. 2 2 Anode 3 10 10 Anode 4 1 1 10 10 0 0 10 10 3 3 10 10 Counts/Accum. Counts/Accum. 2 2 Anode 5 10 10 Anode 6 1 1 10 10 0 0 10 10 52 104 156 208 260 312 364 416 3 10 Record # Counts/Accum. 2 Anode 7 10 1 10 0 10 0 52 104 156 208 260 312 364 416 Record # !"#$#%&'()*'$&+,-'.//0 ! .1 ! ./'23456'7085.844 Friday, August 9, 2013

A Possible Remedy Obs. Data Background Sim. Data +23.96:1.71 m:q 3 3 10 10 Counts/Accum. Counts/Accum. 2 2 Anode 1 Anode 2 10 10 1 1 10 10 0 0 10 10 3 3 10 10 Counts/Accum. Counts/Accum. 2 2 Anode 3 10 10 Anode 4 1 1 10 10 0 0 10 10 3 3 10 10 Counts/Accum. Counts/Accum. 2 2 Anode 5 10 10 Anode 6 1 1 10 10 0 0 10 10 49 98 3 10 Record # Counts/Accum. 2 Anode 7 10 1 10 0 10 0 49 98 Record # DE run 1, Iter. = 150, Cost = 1.76856 Friday, August 9, 2013

New PLS Results  Very Mixed – Several unreasonable features removed "%% ) 670,89,: ;15<=>2,: #&% #%% .,/0123)*45 ! "- $&% $%% &% % ) ! ! ! " ! # ! $ % $ # " ! & ' ()*+,- Friday, August 9, 2013

New PLS Results  But lack of enough data points sometimes makes for enormous errors. %&&& , 9:3/;</= >48?@A5/= *&& )&& (&& '&& 1/23456,-78 ! #0 !&& "&& #&& $&& %&& & , ! ! ! " ! # ! $ ! % & % $ # " +,-./0 Friday, August 9, 2013

New PLS Results  But lack of enough data points sometimes makes for enormous errors. %&&& , 9:3/;</= >48?@A5/= *&& )&& Regardless, the (&& simulation is not '&& 1/23456,-78 ! #0 matching up… !&& "&& #&& $&& %&& & , ! ! ! " ! # ! $ ! % & % $ # " +,-./0 Friday, August 9, 2013

A Final Issue/Interest 3 10 2 10 Counts/Accum. Anode 7 1 10 0 10 0 52 104 156 208 260 312 364 416 Record # DE run 1 Iter = 10 Cost = 4 00 Double peaks show two plasma species – in this case we have pickup ions Friday, August 9, 2013

A Final Issue/Interest 3 10 2 10 Counts/Accum. Anode 7 Spacing shows they’re in the same plane 1 10 0 10 0 52 104 156 208 260 312 364 416 Record # DE run 1 Iter = 10 Cost = 4 00 Double peaks show two plasma species – in this case we have pickup ions Friday, August 9, 2013

A Final Issue/Interest Energy differs by a factor of ~8 (4 for pickup ions) 3 10 2 10 Counts/Accum. Anode 7 Spacing shows they’re in the same plane 1 10 0 10 0 52 104 156 208 260 312 364 416 Record # DE run 1 Iter = 10 Cost = 4 00 Double peaks show two plasma species – in this case we have pickup ions Friday, August 9, 2013