CREATE TABLE table_30970 ("Episode" TEXT, "First broadcast" TEXT, "Andrew and Jacks guest" TEXT, "Jamies guests Peter Crouch replaced Jamie Redknapp as team captain for one week in series 5 ,  episode 2." TEXT, "Scores" TEXT)

When were episodes first broadcast with jessica ennis as andrew and jacks guest?
SELECT "First broadcast" FROM table_30970 WHERE "Andrew and Jacks guest" = 'Jessica Ennis'
SELECT "First broadcast" FROM "table_30970" WHERE "Andrew and Jacks guest" = 'Jessica Ennis'