Exploring Earth at Night

A new MapMaker Interactive layer gives you a view of the Earth at night, as seen from space. This new map is a cloud-free view of our planet acquired by the Suomi National Polar-orbiting Partnership Satellite (Suomi NPP). The image reveals city lights, gas flares, wildfires and other nighttime lights. The imagery was captured in April and October 2012 by a sensor aboard NOAA’s Suomi National Polar-orbiting Partnership Satellite.

We’ve added the updated layer to our MapMaker Interactive, where you can look for global patterns and zoom in to explore the geography of nighttime lights around the world. The map is so rich with geographic information. Here are 3 interesting things I found, just by inspecting it.

Disparity Between North and South Korea
Zoom into the Korean peninsula and you’ll see that the nighttime light usage in South Korea is significantly more noticeable than in the much darker North Korea. Compare this to the population density layer in the MapMaker Interactive to reveal an interesting geographic disparity: The population is dense throughout much of the peninsula, yet the nighttime landscape in South Korea is much brighter.

A view of nighttime lights from North and South Korea.
A view of nighttime lights from North and South Korea.

Offshore Oil in Nigeria
If you drill down to West Africa, you’ll notice bright spots along the Nigerian coast. Much of this is from the lights turned on by the millions of residents of cities like Lagos and Port Harcourt–Nigeria is, after all, one of the top ten most populous country in the world. Other light shines bright off the coast of the country, particularly around the mouth of the Niger River. The offshore oil industry booms in this region, so the nighttime lights come from oil rigs and gas flares from these operations. Nigeria is the largest oil producer in Africa, but their industry is a source of much social and environmental conflict.

Lights at Night - Nigeria
A view of nighttime lights from Nigeria and surrounding African countries.

The Great Lights…Ahem, Lakes
Skirting Lakes Michigan, Huron, Erie, and Ontario is the Great Lakes megalopolis, a series of adjacent metropolitan areas, which appear to form a continuous mass of nighttime lights. Cities within this region include Chicago, Ill. and Milwaukee, Wis. on the western shore of Lake Michigan; Buffalo, N.Y. at the eastern tip of Lake Erie and Toronto on the Canadian side of Lake Ontario. Take a look beyond this region and you’ll find that the Great Lakes megalopolis is really just one of many in the United States and around the world.

Lights at Night - Great Lakes
A nighttime view of lights from the Great Lakes region of the United States and Canada.

Speaking of patterns of light at night, it’s also interesting to study where there are not nighttime lights. Light pollution impedes our view of the night sky and can have other negative impacts on natural ecosystems. Check out this post from our 2011 BioBlitz in Arizona about a citizen science program that has participants measuring the brightness of stars at night from their backyards.

It’s amazing how much we can learn about our world just by studying a map of nighttime lights. Keep exploring and let us know what patterns and features you find interesting in the map!
About the map layer: A joint program by NASA and NOAA, Suomi NPP captured this nighttime image by the satellite’s Visible Infrared Imaging Radiometer Suite (VIIRS). The day-night band on VIIRS 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, and wildfires. This new image is a composite of data acquired over nine days in April and thirteen days in October 2012. It took 312 satellite orbits and 2.5 terabytes of data to get a clear shot of every parcel of land surface. Find out more here.

Written by: Sean O’Connor

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