CREATE TABLE table_48645 ("Discipline" TEXT, "Circuit" TEXT, "Event" TEXT, "Session" TEXT, "Cause" TEXT)

The 1977 Japanese Grand Prix in the open wheel discipline has what session?
SELECT "Session" FROM table_48645 WHERE "Discipline" = 'open wheel' AND "Event" = '1977 japanese grand prix'
SELECT "Session" FROM "table_48645" WHERE "Discipline" = 'open wheel' AND "Event" = '1977 japanese grand prix'