... The most distant object easily visible to the unaided eye is M31, the great Andromeda Galaxy some two million light-years away. But without a telescope, even this immense spiral galaxy - spanning over 200,000 light years - appears as a faint, nebulous cloud in the constellation Andromeda. ... Brightness measurements from different angles have shown Saturn's rings to be about one kilometer thick, making them many times thinner, in relative proportion, than a razor blade. ... Autumn Moon Encore . ...