A few weeks ago, the Cassini spacecraft flew by Saturn. As it did so, it turned its cameras back toward earth and and snapped pictures of it just as the Voyager 1 space craft did so in 1990. If memory serves me correctly (which does not always do anymore) the image of the earth took about one quarter of a pixel of space on the photograph. Now Cassini-Hyguns has taken a slightly higher resolution photograph in which one can even see the moon along with the earth