Procedure: Season the duck inside and out with the salt and pepper.
Squeeze the orange juice over the outside of the duck and put the halves into the cavity with the rosemary.
Roast on an oven rack at 425°F for 45 minutes. Decrease the oven temperature to 350°F and roast for an additional 45 minutes, or until the duck registers 165°F internal temperature (the leg pulls away from the body easily when moved).
Allow the duck to rest for 20 minutes before carving.