Scientists unveiled today an unprecedented new look at our planet at
night. A global composite image, constructed using cloud-free night
images from a new NASA and National Oceanic and Atmospheric
Administration (NOAA) satellite, shows the glow of natural and
human-built phenomena across the planet in greater detail than ever
before.
Many satellites are equipped to look at Earth during the day, when they
can observe our planet fully illuminated by the sun. With a new sensor
aboard the NASA-NOAA Suomi National Polar-orbiting Partnership (NPP)
satellite launched last year, scientists now can observe Earth's
atmosphere and surface during nighttime hours.
The new sensor, the day-night band of the Visible Infrared Imaging
Radiometer Suite (VIIRS), is sensitive enough to detect the nocturnal
glow produced by Earth's atmosphere and the light from a single ship in
the sea. Satellites in the U.S. Defense Meteorological Satellite Program
have been making observations with low-light sensors for 40 years. But
the VIIRS day-night band can better detect and resolve Earth's night
lights.
The new, higher resolution composite image of Earth at night was
released at a news conference at the American Geophysical Union meeting
in San Francisco. This and other VIIRS day-night band images are
providing researchers with valuable data for a wide variety of
previously unseen or poorly seen events.
"For all the reasons that we need to see Earth during the day, we also
need to see Earth at night," said Steve Miller, a researcher at NOAA's
Colorado State University Cooperative Institute for Research in the
Atmosphere. "Unlike humans, the Earth never sleeps."
This new global view and animation of Earth’s city lights is a composite
assembled from data acquired by the Suomi NPP satellite. The data was
acquired over nine days in April 2012 and 13 days in October 2012. It
took 312 orbits to get a clear shot of every parcel of Earth's land
surface and islands. This new data was then mapped over existing Blue
Marble imagery of Earth to provide a realistic view of the planet.
Credit: NASA Earth Observatory/NOAA NGDC
SOURCE: NASA
