Almost five decades ago, two photographs of planet Earth, taken by Apollo missions 8 and 17 respectively, marked both the end and the be-ginning of an era: Earthrise (by William Anders, 1968, Nasa-ID AS8-14-2383HR) and Blue Marble (by Harrison Schmitt, 1972, AS17-148-22727) seemed but an »afterthought«1 – at first sight a hardly noteworthy side product of the dramatic ›space ra…