CREATE TABLE table_18173916_8 (friday VARCHAR2, tuesday VARCHAR2)

which episode was Transmitted on friday if the episode of '414 insanely twisted shadow planet' was transmitted on tuesday?
SELECT friday FROM table_18173916_8 WHERE tuesday = "414 Insanely Twisted Shadow Planet"
SELECT "friday" FROM "table_18173916_8" WHERE "414 Insanely Twisted Shadow Planet" = "tuesday"