Answer based on context:

After finally beating former quarterback Brett Favre in Week 7, the Packers traveled to New Meadowlands Stadium in East Rutherford, NJ to take on the New York Jets. The Packers took a 3-0 lead on a Mason Crosby 20-yard field goal in the first quarter and held that lead until the fourth quarter. Crosby then hit two field goals in the fourth quarter (from 41 and 40 yards respectively) to seal the victory for the Packers. While Aaron Rodgers and the Packer offense sputtered against the vaunted Jet defense, Green Bay's defense excelled in stopping the NFL's second-ranked rushing offense and intercepted Jets quarterback Mark Sanchez twice. The win improved the Packers to 5-3 and in first place in the NFC North.

How many yards was Crosby's shortest field goal?
20