Trying to rebound from their Monday Night road loss to the Seahawks, the Raiders went home for an AFC West rematch with the Denver Broncos.  In the first quarter, the Raiders struck first. Following an interception by cornerback Nnamdi Asomugha, RB LaMont Jordan plunged in for a 1-yard TD run.  The Broncos would respond with QB Jake Plummer completing a 39-yard TD pass to Javon Walker.  In the second quarter, Oakland would regain the lead with kicker Sebastian Janikowski getting a 55-yard and a 20-yard field goal.  However, after a scoreless third quarter, Denver would retake the lead and win with Plummer completing a 1-yard TD pass to FB Kyle Johnson and kicker Jason Elam getting a 24-yard field goal.  Despite a strong defensive effort, including two interceptions from cornerback Fabian Washington, the Raiders lost the game and fell to 2-7.
Question: How many yards was the shortest field goal?
Answer: 20