||I WAS recently amazed by some night-time spacecraft photographs, exemplified by Fig. 1, that present graphic evidence of waste and pollution. These were obtained by the United States Air Force DAPP system which has sensors in the visible 0.4 to 1.1 µm band and an infrared imaging system in the 8 to 13 µm band (ref. 1 and J. L. McLucas, personal communication). The visible band sensor is Capable of responding to very dim light with a controllable threshold (T. O. Haig, personal communication) and it provided these pictures. The lights of cities are clearly visible, as are the aurora, surface features illuminated by moonlight, and fires such as those caused by burning gas from oil fields and refineries. Much power is evidently being generated to light the cities of the world since at the inhabited areas are clearly outlined. It is also apparent that, in the process of extracting liquid petroleum from beneath the surface of the Earth, abundant gas supply has been discovered but is not used. Being unable to contain the gas or to transport it to a user, it is simply burnt.