This new picture from NASA's Cassini probe shows off the peculiarity of Daphnis, a moon so tiny it wasn't discovered until 2005. It's just 8 kilometres (5 miles) across, and irregularly shaped, which gives it a wobbly orbit. ... The Keeler gap is just 42 kilometres (26 miles) wide, and Daphnis' distance varies from Saturn by about 9 kilometres (5.6 miles), while it moves up and down by about 17 kilometres (10.5 miles). This eccentricity, and Daphnis' gravity, causes peaked waves to form on the edges of the gap, in both vertical and horizontal directions. In this new image, taken...