About 47,000 miles (75,639 kilometers) of those roads are part of the Interstate Highway System, established by President Dwight Eisenhower in the 1950s. The United States has more miles of roads than any other nation in the world-4.1 million miles (6.6 million kilometers) to be precise, which is roughly 40 percent more than second-ranked India. While airglow can also be green or blue, red airglow like this comes from excited oxygen atoms at heights of about 90 to 190 miles (150 to 300 kilometers). The glowing line along Earth’s limb-or edge of the atmosphere-is airglow, a type of light that is produced by chemical reactions in the upper atmosphere. The blue-white patch on the far left is a flash of lightning, a common sight for astronauts. In addition to the human activity, the photograph also showcases a few natural splashes of light and color. The same study pointed out that two of the brighter points of light in the area are gas flares emanating from offshore oil infrastructure. According to one estimate based on satellite observations, there were over 500 fishing boats in the area on a single night in September 2014. Many of these vessels are likely fishing boats using bright lights to attract squid and other sea life. North of the city of Surabaya, the capital of East Java province, large numbers of boat lights dot the darkened Java Sea.

The photo, taken on October 20, 2014, captured light from roads and cities, fishing boats, lightning, airglow, and even a few gas flares. To the discerning eye, these lights reveal intricate details of both natural phenomena and the unmistakable footprints of human civilization. However, as this photograph-taken over the Java Sea by a member of the Expedition 42 crew onboard the International Space Station-reveals, at night these “nighttime lights” become visible.

The visible lights produced by modern civilization are often obscured by the more intense light of the Sun during the day.

Night satellite view of earth