Night Life as Seen From Space

Scientists plan satellite to snap pictures of cities at night

3 min read

11 September 2007--The size and shape of the ”human footprint” on Earth might best be seen from space--and in the dark, say scientists. Christopher Elvidge, a researcher at the National Oceanic and Atmospheric Administration's National Geophysical Data Center in Boulder, Colo., and his collaborators have come up with a concept for a satellite mission, called NightSat, which would take pictures of Earth's surface at nighttime with a high-resolution, low-light camera. The purpose is to obtain a complete, cloud-free map of all nighttime lights on Earth on an annual basis.

Lights serve as a kind of geographic marker of human activity on the planet: they tell us information about the location of settlements, how land is used between urban areas, how dynamic population growth and migration is, and what impact urban settlements have on a region's natural resources, weather, and climate. Analyzing changes in nighttime lights over time can provide a model of how human civilization is progressing on the planet and how its relationship to the environment is affected. The concept is simple, so why haven't nighttime lights been mapped already?

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Top Tech 2022: A Special Report

Preview two dozen exciting technical developments that are in the pipeline for the coming year

1 min read
Photo of the lower part of a rocket in an engineering bay.

NASA’s Space Launch System will carry Orion to the moon.

Frank Michaux/NASA

At the start of each year, IEEE Spectrum attempts to predict the future. It can be tricky, but we do our best, filling the January issue with a couple of dozen reports, short and long, about developments the editors expect to make news in the coming year.

This isn’t hard to do when the project has been in the works for a long time and is progressing on schedule—the coming first flight of NASA’s Space Launch System, for example. For other stories, we must go farther out on a limb. A case in point: the description of a hardware wallet for Bitcoin that the company formerly known as Square (which recently changed its name to Block) is developing but won’t officially comment on. One thing we can predict with confidence, though, is that Spectrum readers, familiar with the vicissitudes of technical development work, will understand if some of these projects don’t, in fact, pan out. That’s still okay.

Engineering, like life, is as much about the journey as the destination.

See all stories from our Top Tech 2022 Special Report

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