The student pilot reported that he approached the privately owned rough grass airstrip and observed that it was covered with snow. After evaluating the snow’s depth as being only a few inches, the pilot landed. During rollout, the airplane decelerated quickly and nosed over, bending its vertical stabilizer, wings, and lift struts. Upon exiting the airplane, the pilot ascertained that, in fact, the snow was between 6 and 8 inches deep. The student pilot’s certified flight instructor reported that he had not endorsed the student’s flight record logbook in over 90 days, and he had not authorized the student to fly to the accident airport. The student was not current in the airplane.