AT 60 RE FROM EARTH IN LUNAR ORBIT THE TWO ARTEMIS SPACECRAFT SPEND AMPLE TIME IN THE UNDISTURBED SOLAR WIND PROVIDING RAPID SAMPLING OF THE PLASMA AND FIELDS TO ACCUMULATE A LARGE LIBRARY OF INTERPLANETARY SHOCK CROSSINGS. SEPARATED BY A SHORT BASELINE THIS SET OF DUAL SHOCK MEASUREMENTS ALLOWS US TO EXAMINE THE STABILITY OF THE INTERPLANETARY SHOCK IN SPACE AND TIME AS NEVER BEFORE DONE. FURTHER THIS COLLECTION ALLOWS A NOVEL EXPERIMENT IN WHICH WE CAN WATCH THE SHOCK RECONSTRUCTION PROCESS AFTER THE SHOCK IS DISRUPTED BY THE MOON. INTERPLANETARY SHOCK WAVES ARE A FUNDAMENTAL PLASMA PROCESS AND ARE CRITICAL TO THE ACCELERATION OF CHARGED PARTICLES. IN THE LAST SEVERAL DECADES STUDIES USING MULTIPLE SPACECRAFT OBSERVATIONS HAVE LARGELY COVERED THE MHD SCALE OF THE SHOCK AND REVEALED THE SHOCK EVOLUTION ON SPATIAL SCALES FROM 105 TO SEVERAL MILLIONS OF KILOMETERS. HOWEVER KINETIC PROCESSES THAT DEPEND ON THE SPECIFIC LOCAL SHOCK STRENGTH THE MAGNETIC STRUCTURE ENCOUNTERED AND PROCESSES ON THE ION GYRO SCALE ARE NOT COVERED BY PREVIOUS STUDIES. MOREOVER THE NEAR PRESENCE OF THE MOON ALLOWS US TO PERTURB THE SHOCK IN A KNOWN WAY AND WATCH IT RECOVER IN A MANNER THAT MAY NOT BE SIMILAR TO THE PROCESSES THAT WE HAVE KNOWN. BASED ON THE UNIQUENESS OF THE ARTEMIS DATA THAT PROVIDE SAMPLE RATES OF 4 HZ FOR THE MAGNETIC FIELD AND 0.25 HZ FOR PLASMA MOMENTS DURING FAST SURVEY AND THAT ARISE FROM TWO SPACECRAFT WITH SEPARATION RANGING FROM ~5X102 TO 5X104 KM (~0.08 7.8 RE) WE ADDRESS TWO IMPORTANT QUESTIONS OF THE FUNDAMENTAL IMPORTANCE TO HELIOSPHERIC PLASMA PHYSICS: 1) WHAT IS THE SHOCK S 3D-STRUCTURE SIGNATURE ON SCALES CLOSE TO THE GYRO RADIUS? ARTEMIS ALLOWS US TO UNDERSTAND THE SHOCK STATIONARITY OVER A SPATIAL DIMENSION OF A FEW EARTH RADII AND TEMPORAL SCALE OF 2 MINUTES OR LESS INCLUDING THE SPATIAL AND TEMPORAL MICROSTRUCTURE WITHIN THE SHOCK LAYER AND PROVIDES A MEASURE OF THE SHOCK SUPER-CRITICALITY AS CHARACTERIZED BY THE STRENGTH OF THE SHOCK AND SHOCK FOOT AND OVERSHOOT. 2) HOW DO SHOCKS SELF-RECONSTRUCT AFTER BEING INTERRUPTED BY AN OBSTACLE? THE PLANAR SHOCK WAVES ARE DISRUPTED WHEN ENCOUNTERING THE MOON. IF THE SHOCK CAN MEND ITSELF IN SUCH AN ENVIRONMENT WHAT IS THE PHYSICS BEHIND THE RECOVERY PROCESS? AND WILL THE HEALED AREA EVENTUALLY BE MELDED INTO THE ORIGINAL SHOCK TO REMAKE THE SHOCK AS UNIFORM AS BEFORE THE RUPTURE? THE TECHNICAL APPROACH STRATEGIES ARE COMPRISED OF DATA ANALYSIS AND DATA COMPARISON WITH APPROPRIATE THEORETICAL MODELS FOR THE FIRST QUESTION AND CONDUCTING 3D HYBRID SIMULATIONS FOR THE SECOND QUESTION. FIVE STEPS OF DATA ANALYSIS ARE USED TO IDENTIFY SHOCKS TO OBTAIN SHOCK PARAMETERS SHOCK UP AND DOWNSTREAM PLASMA AND MAGNETIC FIELD CONDITIONS SHOCK CRITICALITY AND TO ANALYZE SHOCK STATIONARITY AND STRUCTURE AT THE SHOCK LAYER. THEORIES ABOUT THE DOWNSTREAM PLASMA BEHAVIOR THE SHOCK STRUCTURE THE PARTICLE ACCELERATION THE PHYSICS OF SHOCK CRITICALITY AND SHOCK STEEPENING ARE TESTED USING THE RESULTS FROM THE FIVE STEPS. WE WILL OBTAIN 3D ELECTROMAGNETIC HYBRID (KINETIC IONS FLUID ELECTRONS) SIMULATIONS TO UNDERSTAND THE ROLE OF SHOCK GEOMETRY AND SHOCK TYPE IN THE SHOCK RECONSTRUCTION IN THE LUNAR WAKE. SIX WAKE EVENTS WILL BE USED FOR SIX HYBRID RUNS WITH SOLAR WIND OBSERVATIONS AS THE INPUT OF THE RUN AND THE COUNTERPART MEASUREMENT IN THE WAKE FOR COMPARISON WITH THE SIMULATION RESULTS. THIS PROPOSED INVESTIGATION FULLY COMPLIES WITH THE SCIENTIFIC SCOPE REQUIREMENT OF THE NASA/HSR PROGRAM AND ADDRESSES THE 5TH SCIENCE AREA OF HELIOSPHERIC PLASMA PROCESSES TURBULENCE WAVES COMPOSITION. RESULTS OF THIS INVESTIGATION WILL PROVIDE NEW INSIGHT INTO SHOCK STATIONARITY AND STRUCTURE ON ION GYRO SCALES AND INTO THE SHOCK RECONSTRUCTION AND STEEPENING. IN ADDITION TO THE SCIENCE PUBLICATIONS OF THIS INVESTIGATION WE PROVIDE PUBLIC ACCESS TO THE ARTEMIS SHOCK DATABASE BY POSTING IT ON THE THEMIS WEBSITE.
$567,998FY2017National Aeronautics and Space AdministrationNASA
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