Propagation of the sudden commencement of July 8, 1966, to the magnetotail

Abstract

e r p l a n e t a r y space by IMP-3 and Explorer 33, we e s t i m a t e t h e i n t e rp l a n e t a r y shock speed t o be approximately 500 km/sec, w i t h an Alfvhn Mach number f o r t h e shock about 1 . 2 . This speed i s c o n s i d e r a b l y lower t h a n t h a t deduced by Lazarus and Binsack from t h e i r plasma measurements on E x p l o r e r 33, namely, 700 km/sec.