Coming off their divisional road win over the Dolphins, the Jets played their Week 2 home opener against their AFC East foe, the New England Patriots.  The Jets had the first opportunity to score in the first quarter, but a 31-yard field goal attempt by new kicker Jay Feely was wide right.  New York then trailed as Patriots kicker Stephen Gostkowski got a 21-yard field goal.  In the second quarter, the Jets continued to trail as Gostkowski kicked a 37-yard field goal.  Brett Favre got the Jets down to the 3-yard line, but after three running plays resulting in 0 net yardage, the Jets settled for a 21-yard field goal to get on the board. In the third quarter, New England capitalized on an interception by Brandon Meriweather off a Brett Favre pass. The Patriots increased its lead 6 plays later as RB Sammy Morris got a 1-yard TD run and Gostkowski nailed a 28-yard field goal.  In the fourth quarter, the Jets tried to rally as QB Brett Favre completed a 2-yard TD pass to WR Chansi Stuckey.  However, the Patriots pulled away with Gostkowski's 27-yard field goal.

Based on the above article, answer a question. How many yards was Stephen Gostkowski's shortest field goal?
21