Triangular shape with long, blunt nose; light fluorescent green; appeared suddenly, moving east.Object suddenly appeared and glided across the highway, eastbound toward the mountains; disappeared into clouds, reappeared, and then went out of sight over the mountains. Object was fluorescent, light green; size unknown, however appeared about the size of a low-flying jetliner. There was an appearance of sparks emanating from the right, rear of the object.