While en route to his destination, at 4,500 feet above mean sea level and during night visual meteorological conditions, the pilot of a Mooney M20G experienced a total loss of engine power. The pilot attempted to restart the engine but was unsuccessful. He then executed the forced landing procedure and glided the airplane towards a "dark spot" on the ground. The airplane struck trees and then the ground. Postaccident examination of the airplane and engine did not reveal any preimpact malfunctions. A review of a carburetor-icing chart revealed that atmospheric conditions at the time of the accident were conducive to "serious icing at cruise power." A representative from the engine manufacturer advised that there was in excess of a 90 percent probability of developing carburetor ice at the time of the accident, based on local conditions. The pilot reported that he did not normally use carburetor heat when flying, as the weather was usually warm in the area of the country he operated in.