Interesting photo? On this self-portrait of astronaut Clay Anderson, the space helmet reflects earth. It was taken by the astronaut during the shuttle orbiter Endeavour's mission to expand the space station last August. The large curvature of the Earth appearing in the visor reflection is not the true curvature of our spherical Earth, but rather an artifact of the curve of the space helmet. Earth's horizon appears only slightly curved when viewed from the height of the International Space Station -- approximately 400 kilometers.