"The last time anyone took a photograph from above low Earth orbit that showed an entire hemisphere (one side of a globe) was in 1972 during Apollo 17. NASA’s Earth Observing System (EOS) satellites were designed to give a check-up of Earth’s health. By 2002, we finally had enough data to make a snap shot of the entire Earth. So we did. The hard part was creating a flat map of the Earth’s surface with four months’ of satellite data. Reto Stockli, now at the Swiss Federal Office of Meteorology and Climatology, did much of this work. Then we wrapped the flat map around a ball. My part was integrating the surface, clouds, and oceans to match people’s expectations of how Earth looks from space. That ball became the famous Blue Marble.
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