Hoping to rebound from their embarrassing road loss to the Giants, the Seahawks returned home for a Week 6 duel with the Green Bay Packers, as head coach Mike Holmgren faced his former team for the last time.  Also, QB Seneca Wallace was unable to play due to a knee injury he suffered from last week.  QB Charlie Frye was given the start. In the first quarter, Seattle trailed early as Packers kicker Mason Crosby got a 29-yard field goal.  In the second quarter, the Seahawks took the lead as kicker Olindo Mare got a 50-yard field goal, while Frye completed a 6-yard TD pass to rookie TE John Carlson.  Green Bay tied the game as QB Aaron Rodgers got a 1-yard TD run. In the third quarter, the Packers regained the lead as Rodgers completed a 45-yard TD pass to WR Greg Jennings.  In the fourth quarter, Green Bay pulled away as Rodgers completed a 1-yard TD pass to FB John Kuhn, along with Crosby nailing a 51-yard field goal.  Seattle tried to come back as Frye completed a 5-yard TD pass to WR Keary Colbert, but the Packers' defense was too much.
How many yards longer was Mare's first half field goal compared to Crosby's first half field goal?
21