CREATE TABLE table_23548 ("#" TEXT, "Original title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original airdate" TEXT, "Production code" TEXT)

What was the production code for 'down to earth'?
SELECT "Production code" FROM table_23548 WHERE "Original title" = 'Down to Earth'
SELECT "Production code" FROM "table_23548" WHERE "Original title" = 'Down to Earth'