KRAKÓW, POLAND—According to a Live Science report, researchers led by archaeologist Radosław Palonka of Jagiellonian University employed laser scanning and photogrammetry to create highly detailed 3-D models of 800-year-old artworks inscribed on rock surfaces at southwestern Colorado’s Castle Rock Pueblo. At sunset on days around the time of the midwinter solstice and the spring and fall equinoxes, Palonka explained, the sunlight and shadows appear to move through the carved spirals and grooves of the petroglyphs. The researchers also noted that similar petroglyphs at nearby Sand Canyon are illuminated in the morning and early afternoons around the time of the summer solstice. Palonka thinks such engravings were probably used to mark the seasons. Several panels of previously unrecorded rock art were also studied, he added. To read about Cherokee ritual imagery in the deep caves of the American South, go to "Artists of the Dark Zone."