NASA scientists have published new global maps of the Earth at night, providing the richest and clearest views of most of the planet’s settlements. Satellite images of the Earth at night (often referred to as “night illumination”) have been a fundamental research tool for 25 years. Created once a decade, maps are ubiquitous in pop culture, economics, sociology, and environmental research.
Continuing the theme of photos of the Earth from space, I present to you a new selection of amazing shots. All photographs were taken at the NASA Observatory by Joshua Stevens using Suomi NPP VIIRS data from NASA’s Goddard Space Flight Center. Since the launch of the satellite in 2011, scientists at the NPP team have been analyzing night light data and developing new software and algorithms to make night light images clearer, more accurate and easily accessible. Today, they are on the verge of providing a daily, high-quality night view of the Earth and are ready to provide a similar service to the scientific community this year.
Scientists have been creating remote sensing techniques to filter out stray light sources, receive a better and more consistent signal, and process the image instantly. A special filter called VIIRS has been developed, the first satellite-based instrument capable of making quantitative measurements of light emission. It allows researchers to distinguish between the intensity, types, and sources of nighttime lighting across multiple years of data. The Suomi satellite observes most of the Earth’s locations at approximately 1:30 PM and 1:30 AM each day, tracing the planet in vertical 3,000-kilometer bands from pole to pole. VIIRS instantly performs all the necessary transformations, and the data appears in the public domain within a matter of hours.
Armed with more accurate nighttime instruments, NASA’s team is now automating processing so that users can view Earth’s nightscapes virtually online. The tool has potential in short-term weather forecasting and emergency response. “With VIIRS, we can observe short-term changes caused by power outages due to conflicts, storms, earthquakes and blackouts,” said one developer. “We can see the cyclical changes driven by human activity, including holiday lighting and seasonal migrations. We can also observe gradual changes as a result of urbanization, emigration, economic changes and electrification.”
In continuation of the topic, I advise you to admire the incredible photographs of space from NASA in a separate article.