NASA has just released some of the clearest views ever seen of the Earth at night, providing a stunning and insightful look at our planet when the Sun goes down.
The series of images have been nicknamed the "Black Marble" in reference to the most famous image of Earth, the "Blue Marble", taken in 1972 by the crew of the Apollo 17 spacecraft. These new images come straight from the Suomi NPP weather satellite, which is equipped with the Visible Infrared Imaging Radiometer Suite. This cutting-edge sensor is able to detect photons of light reflected from Earth in 22 different wavelengths
NASA had to take a deep look at how light is reflected and radiated by Earth’s land, seasonal vegetation, snow, ice, atmosphere, ocean, and even auroras to craft the maps. On top of that, they had to keep an eye out for the phase of the Moon and account for how this would affect light levels. Clouds and a Sun glint on the Earth's edge are then added post-production for aesthetic effect using previously obtained scientific data.
The Americas, Africa & Europe, and Asian & Australasia as seen by night. NASA Earth Observatory images by Joshua Stevens, using Suomi NPP VIIRS data from Miguel Román, NASA's Goddard Space Flight Center
The last map of this kind was released in 2012. The world has since undergone more urbanization and a further rise in population, which means there are more city lights, highways, and street lamps for the weather satellite to "soak up".
Along with being easy on the eye, the maps and data have a range of applications for Earth science and can be used for a whole host of economic, social science, and real-life disaster response projects. In 2016, for example, NASA used the satellite to gather data on power outages for federal authorities.
“Thanks to VIIRS, we can now monitor short-term changes caused by disturbances in power delivery, such as conflict, storms, earthquakes and brownouts," project leader Miguel Román said in a statement. "We can monitor cyclical changes driven by recurring human activities such as holiday lighting and seasonal migrations. We can also monitor gradual changes driven by urbanization, out-migration, economic changes, and electrification. The fact that we can track all these different aspects at the heart of what defines a city is simply mind-boggling."
Composite image of the US at night in 2016. NASA Earth Observatory images by Joshua Stevens, using Suomi NPP VIIRS data from Miguel Román, NASA's Goddard Space Flight Center