News•December 5, 2012

NASA Dazzles With 'Black Marble' Image of Earth at Night

SAN FRANCISCO —Taking advantage of new satellite capabilities, scientists from NASA and the National Oceanic and Atmospheric Administration (NOAA) released new imagery of Earth at night, providing an improved “Black Marble” counterpart to the iconic “Blue Marble” image of the planet during the day. The images, which were released on Wednesday here at the annual meeting of the American Geophysical Union, provide a clearer picture of the planet at night than ever before.

The imagery was generated by a sensor carried aboard the NASA-NOAA Suomi National Polar-orbiting Partnership (NPP) satellite, known as the Visible Infrared Imaging Radiometer Suite, or VIIRS. As its name suggests, the VIIRS detects visible light, and it is sensitive enough to detect the nocturnal glow produced by the Earth’s atmosphere, and the light from a single fishing vessel at sea. The day-night band from VIIRS is helping scientists monitor carbon emissions from natural gas and oil drilling operations, since it can detect flaring operations at night. The data has proven useful for monitoring wildfires, and has even provided a rare glimpse into upper atmospheric waves that can be generated from massive complexes of thunderstorms.

“This is not your father’s low-light sensor,” said Steve Miller, a researcher at NOAA's Colorado State University Cooperative Institute for Research in the Atmosphere. He showcased the satellite’s capabilities, noting that the imagery scientists have retrieved from it represents a “paradigm shift” in what can be done under low-light conditions.

It even provided a detailed analysis of the extent of power outages in the New York City region from Hurricane Sandy, right down to the divide between upper Manhattan, which had power, and lower Manhattan, where electricity was shut off as the storm surge flooded the infrastructure underneath the city.

Nighttime city lights of America.
Click to enlarge the image. Credit: NASA/NOAA.

The VIIRS sensor provides scientists with six times greater spatial resolution compared to older satellite instruments, which is helping researchers shed insight on everything from global carbon emissions to compliance with fishing regulations.

According to NASA and NOAA, the day-night band doesn’t operate like a typical camera, which takes a picture in a single exposure. Instead, it produces an image by repeatedly scanning a scene and resolving it as millions of pixels. Then the day-night band reviews the amount of light present in each pixel, amplifying very dark pixels and limiting the saturation of very bright pixels.

“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,” Miller said in a press release.

The “black marble” image was generated using two months of day-night band data.

Nighttime city lights of Africa.
Click to enlarge the image. Credit: NASA/NOAA.

“I think this is a new frontier for science in the low-light imagery realm for meteorology,” Miller said.

The NPP satellite carries other instruments considered to be crucial to medium-range weather forecasting, and it is scheduled to be in service through 2017. However, delays in the next generation of polar-orbiting satellites will leave the U.S. with a gap in satellite coverage that is expected to last for more than a year, potentially degrading weather forecast accuracy.

Nighttime city lights of Asia.
Click to enlarge the image. Credit: NASA/NOAA.

Nighttime satellite image showing bright spots in North Dakota, particularly near Williston, indicating flaring operations from oil and gas drilling.
Click to enlarge the image. Credit: NASA/NOAA.

Satellite image showing the Aurora Australis over Antarctica, otherwise known as the “Southern Lights.”
Click to enlarge the image. Credit: NASA/NOAA.

“Flat Earth” image of the planet at night.
Credit: NASA/NOAA