Night lights

An unprecedented new view of Earth at night shows Hono­lulu as a tiny speck of light in the vast Pacific, as well as a bright and presumably bustling Asia — all but for North Korea.

The contrast between North Korea and South Korea is particularly stark. With North Korea nearly as dark as the surrounding ocean, South Korea looks like an island instead of part of a peninsula.

"The contrast illustrates dramatically the difference between a prosperous, developed economy and an austere, failing economy," said Denny Roy, a Korea expert at the East-West Center. "On most photos like this, only the North Korean capital of Pyong­yang appears to be well lit."

Ralph Cossa, another Asia expert, agrees.

"The North remains insulated and isolated, and its people live in darkness, both literally and figuratively," remarked Cossa, president of the Hono­lulu-based Pacific Forum CSIS, affiliated with the Center for Strategic and International Studies.

Both Roy and Cossa commented on the NASA image for the Star-Advertiser.

"It is interesting to note that when I first went to Korea, in 1969 as an Air Force lieutenant, South Korea was the poorer of the two," said Cossa.

But while South Korea embraced free-market capitalism and ultimately democracy, he said, North Korea did not.

"The North remained a feudal state, now being run by the third generations of iron fists, while being sheltered by China," he said.

Regarding China, he said, "China’s illumination is mostly along the coast and at bright spots interspersed around the country along with a lot of still dim areas. Today there are two Chinas: The first-world industrialized China, mostly along the coast and in major population centers, and the third-world rural China. The gap between the two is growing and remains one of the greatest challenges facing the new leadership in Beijing today."

The nighttime image, cloud-free over land, was compiled by the Suomi National Polar-orbiting Partnership satellite launched last year by NASA in cooperation with the National Oceanic and Atmospheric Administration. It was made public Dec. 5 at the annual meeting of the American Geophysical Union in San Francisco.

This new global view, which also comes in animated form showing Earth’s rotation, is a composite assembled from data acquired over nine days in April and 13 days in October. It took 312 orbits to get a clear shot of every parcel of Earth’s land surface and islands, NASA says.

The onboard sensor, known as the Visible Infrared Imaging Radiometer Suite, is sensitive enough to detect the light from a single ship at sea, the space agency said. Satellites in the U.S. Defense Meteorological Satellite Program have been making observations in low light for 40 years, but the VIIRS can better detect and focus on Earth’s night lights.

The sensor detects light in a range of wavelengths from green to near-infrared, and uses filtering techniques to observe signals such as city lights, gas flares, auroras, wildfires and reflected moonlight.

"The night is nowhere as dark as we might think," said Steve Miller, a researcher at NOAA’s Colo­rado State University Cooperative Institute for Research in the Atmosphere.

Unlike a camera that captures a picture in one exposure, the instrument produces an image by repeatedly scanning a scene and turning it into millions of individual pixels. Then it reviews the amount of light in each pixel.

If it is very bright, a low-gain mode prevents the pixel from oversaturating. If the pixel is very dark, the signal is amplified.

"It’s like having three simultaneous low-light cameras operating at once, and we pick the best of various cameras, depending on where we’re looking in the scene," said Miller.

———

On the Net:

» NASA animation : www.nasa.gov/mission_pages/NPP/news/earth-at-night.html