Two weeks after Hurricane Maria hit Puerto Rico, NASA released satellite images comparing light emitted from the U.S. territory before and after the island was devastated by the storm. Areas once lit up are have gone dark, and the visual comparison is absolutely astonishing. Even weeks after Maria swept through the island, power has not been restored — and may not be for months.
The photos were taken on Sept. 27 and 28 and then composited for accuracy. In doing so, NASA explained, they eradicated complications like cloud cover, which could block light emissions. Some cloud cover was unavoidable, particularly on the island's southeastern and western regions, but the differences are still stark, particularly in the capital, San Juan.
NASA didn't just take these photos for the emotional impact, however; there's a practical side. By taking high-quality photos, the organization makes it easier for responders to plan. They at once are able to track the areas that were hit the hardest and can also keep tabs on how long the power has been out in these different regions.
"That is exactly why teams of scientists at NASA are working long days to make sure that groups like the National Guard and [FEMA] get high-quality satellite maps of power outages in Puerto Rico," NASA wrote on the organization's Earth Observatory website.
Adam Voiland, a science writer for NASA, explained their process:
A team of scientists from NASA’s Goddard Space Flight Center and Marshall Space Flight Center processed and corrected the raw data to filter out stray light from the Moon, fires, airglow, and any other sources that are not electric lights. Their processing techniques also remove as much other atmospheric interference—such as dust, haze, and thin clouds—as possible.
In other words, you are truly seeing, to the best of their ability, only light fueled by electricity.
It almost goes without saying that the images with more light cover, marked "baseline," are the images taken before Hurricane Maria devastated most of Puerto Rico's electric grid. As shown, NASA even highlighted some specific places and landmarks, such as the San Pablo Hospital, in San Juan.
NASA retrieved the photos using a "Visible Infrared Imaging Radiometer Suite," or VIIRS, for short. Specifically, they used a "day-night band, which detects light... from green to near-infrared... light from fires and oil wells, lightning, and emission from other cities or human activity."
As of Oct. 5, almost all of the island is without electricity, according to Puerto Rico's government. No one is entirely certain how long electricity will be out, but estimates range from four to six months.
As Brian Resnick and Eliza Barclay write in Vox, that's four to six months that millions of Americans will not have, "air conditioning in the tropical climate, half a year that electric pumps can’t bring running water into homes, half a year when even the most basic tasks of modern life are made difficult."
The concept of going up to six months without power is mind-boggling for most Americans on the mainland. As the New York Times pointed out, Puerto Ricans have a resilient mindset when it comes to storms and droughts, but losing power is an entirely different ballgame.
Those who can are stocking up on electric generators, but those are expensive. Some donations are coming in, but the sustainability of relying on them for the longterm is dubious. Generators rely on diesel fuel, and Reuters reported that its supply is extremely limited.
Immediately following the storm, the Trump Administration was heavily criticized for not responding to the disaster quickly enough. And to make things worse, President Trump and San Juan Mayor Carmen Yulín Cruz have been in a verbal battle, playing out in the press and on Twitter. Cruz, quite literally, has been begging for help. When she criticizes Trump, he criticizes her leadership in return, or claims that Puerto Rican leaders "want everything done for them."
The fact is that lives are literally at stake, and more than 3.4 million Americans are suffering. The proof is in the photos.
Images: Joshua Stevens, using data courtesy of Miguel Román, NASA GSFC, and Andrew Molthan, NASA MSFC/NASA