By Alex Stambaugh, Amanda Musa, CNN(CNN) — A mysterious object that cracked a windshield on a United Airlines flight, injuring a pilot and forcing an emergency landing, may have been a weather balloon. United Flight 1093, a Boeing 737 traveling from Denver to Los Angeles, landed safely in Utah Thursday with 134 passengers and six crew members onboard, according to the airline. Air traffic control audio from LiveATC.net showed the pilots remained calm and declared an emergency as they diverted to land at Salt Lake City. The first officer in the cockpit was treated for minor injuries upon the plane’s landing, the Salt Lake City Fire Department said. Additionally, we are further accelerating our plans to use live flight data to autonomously avoid planes, even if the planes are at a non-standard altitude.