Like every steady electric current, it too must flow in a closed circuit, and the closing occurs in two branches that follow the magnetopause around either tail.
(it; too must flow; in a closed circuit) (the closing; occurs; L:in two branches) (two branches; follow; the magnetopause; around; either tail)
it the closing two branches
too must flow occurs follow
in a closed circuit
L:in two branches
the magnetopause around either tail