HOT FLOW ANOMALIES (HFAS) AND FORESHOCK BUBBLES (FBS) ARE FREQUENTLY OBSERVED IN EARTH S FORESHOCK. THEY FORM WHEN FORESHOCK IONS INTERACT WITH SOLAR WIND DISCONTINUITIES. BECAUSE OF THEIR VERY LOW DYNAMIC PRESSURE THEY CAN RESULT IN SIGNIFICANT DISTURBANCES AT THE BOW SHOCK MAGNETOSHEATH MAGNETOPAUSE AND CONSEQUENTLY THE MAGNETOSPHERE-IONOSPHERE SYSTEM. THEY ARE ALSO FOUND TO BE EFFICIENT PARTICLE ACCELERATORS INCREASING PARTICLE ACCELERATION EFFICIENCY AT THE BOW SHOCK. DESPITE THEIR IMPORTANCE THEIR FORMATION CONDITIONS ARE STILL NOT FULLY UNDERSTOOD. PREVIOUS STUDIES HAVE DETERMINED THEIR FAVORABLE SOLAR WIND CONDITIONS. HOWEVER IT SHOULD BE THE FORESHOCK ION CONDITIONS THAT DIRECTLY DETERMINE THEIR FORMATION AND THE ROLE OF SOLAR WIND CONDITIONS IS TO AFFECT THE FORESHOCK ION PROPERTIES. WE PROPOSE TO USE MMS OBSERVATIONS TO DETERMINE THE FORESHOCK ION CONDITIONS THAT FAVOR HFA/FB FORMATIONS. THE STUDY CONSISTS OF TWO PARTS. WE WILL FIRST CONDUCT A STATISTICAL STUDY OF FORESHOCK ION PROPERTIES AROUND EACH HFA/FB EVENT (~130 IN OUR MMS DATABASE). BY COMPARING THEM WITH BACKGROUND FORESHOCK ION PROPERTIES WHENEVER MMS IS IN THE FORESHOCK WE WILL THUS DETERMINE THE FAVORABLE FORESHOCK ION CONDITIONS AND HOW THEY ARE RELATED TO THE SOLAR WIND SPEED DENSITY MAGNETIC FIELD STRENGTH AND LOCAL BOW SHOCK CONDITIONS (MACH NUMBER ... ...). THE NEXT STUDY IS A MULTIPLE-CASE STUDY (&GT;10 EVENTS) ABOUT THE RELATIONSHIP BETWEEN THE FAVORABLE FORESHOCK ION CONDITIONS AND THE PROPERTIES OF SOLAR WIND DISCONTINUITIES (THICKNESS SHEAR ANGLE ORIENTATION). WE WILL USE THEMIS/ARTEMIS TO OBSERVE THE DRIVER DISCONTINUITIES IN THE PRISTINE SOLAR WIND AND MMS NEAR THE BOW SHOCK TO OBSERVE THE HFAS/FBS AND THE ASSOCIATED FORESHOCK ION PROPERTIES. THESE TWO STUDIES ARE THE NECESSARY STEP TOWARDS A QUANTIFIED FORMATION MODEL OF HFAS/FBS WHICH WILL HELP PREDICT THEIR SPACE WEATHER EFFECTS AND THEIR ROLES IN OTHER SHOCK ENVIRONMENTS SUCH AS ASTROPHYSICAL SHOCKS WITHOUT IN-SITU OBSERVATIONS.