For nearly 25 years, satellite images of Earth at night have served as a fundamental research tool, while also stoking public curiosity. These images paint an expansive and revealing picture, showing how natural phenomena light up the darkness and how humans have illuminated and shaped the planet in profound ways since the invention of the light bulb 140 years ago.
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A Landsat 8 true-color daytime image from March 27, 2018 shows the landscape before the eruption. Then a time series of Landsat 8 nighttime thermal, shortwave infrared, and near infrared imagery shows the progression of the lava flows from May 16 to August 13. The thermal band (in red) reveals not only the very hot lava, but also cooling lava, which is still hotter than background areas. Shortwave infrared (in the blue channel) can image hot lava through clouds and smoke that block the thermal channel. By August 13, no active lava is visible from space, though the recently deposited lava still glows in the thermal bands even through February 12, 2019. Finally, a February 26, 2018 daytime image reveals the new coastline created by the eruption.
The Operational Land Imager (OLI) on Landsat 8 acquired the data for this false-color view of the lava flow as it appeared on the night of May 23, 2018. The image is based on OLI’s observations of shortwave infrared and green light (bands 6-5-3). It was cloudy when the data were acquired, but a small break in the clouds made it possible to image the lava flows. Lava from fissure 22 extends all the way to Hawaii’s southeastern coast and is entering the ocean near MacKenzie State Park. Though it is routine for lava from Kilauea to reach the ocean, this is a new entry point. The purple areas surrounding the flows are clouds lit from below. The animation also makes use of a daytime-image from OLI, with information about the location of roads and coastlines.
Geologists with the Hawaiian Volcano Observatory are monitoring the fissure eruptions closely. While seismometers and other ground-based instruments can track the underground movement of magma to some degree, it is not possible to predict with a high degree of accuracy how long a particular fissure will remain active or how much lava it will produce.
Forecasters were most concerned about Irma, which was on track to make landfall in densely populated South Florida on September 10 as a large category 4 storm. Meanwhile, category 2 Hurricane Katia was headed for Mexico, where it was expected to make landfall on September 9. And just days after Irma devastated the Leeward Islands, the chain of small Caribbean islands braced for another blow—this time from category 4 Hurricane Jose.
The Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite captured the data for a mosaic of Katia, Irma, and Jose as they appeared in the early hours of September 8, 2017. The images were acquired by the VIIRS “day-night band,” which detects light signals in a range of wavelengths from green to near-infrared, and uses filtering techniques to observe signals such as city lights, auroras, wildfires, and reflected moonlight. In this case, the clouds were lit by the nearly full Moon. The image is a composite, showing cloud imagery combined with data on city lights.
These before-and-after images of Puerto Rico’s nighttime lights are based on data captured by the Suomi NPP satellite. The data were acquired by the Visible Infrared Imaging Radiometer Suite (VIIRS) “day-night band,” which detects light in a range of wavelengths from green to near-infrared, including reflected moonlight, light from fires and oil wells, lightning, and emissions from cities or other human activity.
One pair of images shows differences in lighting across the entire island, while the other pair shows lighting around San Juan, capital of the commonwealth. One image in each pair shows a typical night before Maria made landfall, based upon cloud-free and low moonlight conditions; the second image is a composite that shows light detected by VIIRS on the nights of September 27 and 28, 2017. By compositing two nights, the image has fewer clouds blocking the view. (Note: some clouds still blocked light emissions during the two nights, especially across southeastern and western Puerto Rico.) The images show widespread outages around San Juan, including key hospital and transportation infrastructure.
This image of Earth at night in 2016 was created with data from the Suomi National Polar-orbiting Partnership (NPP) satellite launched in October 2011 by NASA, the National Oceanic and Atmospheric Administration, and the U.S. Department of Defense. Each pixel shows roughly 0.46 miles (742 meters) across.
Scientists use the Suomi NPP night-lights dataset in many ways. Some applications include: forecasting a city’s energy use and carbon emissions; eradicating energy poverty and fostering sustainable energy development; providing immediate information when disasters strike; and monitoring the effects of conflict and population displacement. Scientists at NASA are working to automate nighttime VIIRS data processing so that data users are able to view nighttime imagery within hours of acquisition, which could lead to other potential uses by research, meteorological, and civic groups.
This image of Earth at night in 2016 was created with data from the Suomi National Polar-orbiting Partnership (NPP) satellite launched in October 2011 by NASA, the National Oceanic and Atmospheric Administration, and the U.S. Department of Defense. Each pixel shows roughly 0.46 miles (742 meters) across.
Scientists use the Suomi NPP night-lights dataset in many ways. Some applications include: forecasting a city’s energy use and carbon emissions; eradicating energy poverty and fostering sustainable energy development; providing immediate information when disasters strike; and monitoring the effects of conflict and population displacement. Scientists at NASA are working to automate nighttime VIIRS data processing so that data users are able to view nighttime imagery within hours of acquisition, which could lead to other potential uses by research, meteorological, and civic groups.
Scientists use the Suomi NPP night-lights dataset in many ways. Some applications include: forecasting a city’s energy use and carbon emissions; eradicating energy poverty and fostering sustainable energy development; providing immediate information when disasters strike; and monitoring the effects of conflict and population displacement. Scientists at NASA are working to automate nighttime VIIRS data processing so that data users are able to view nighttime imagery within hours of acquisition, which could lead to other potential uses by research, meteorological, and civic groups.