A narrow barrier island protects the Lagoon of Venice from storm waves in the northern Adriatic Sea, and breakwaters protect inlets to the lagoon. Red tiles on the roofs of Venice contrast with the grays of the sister city of Mestre, and the cities are joined by a prominent causeway.
What appears to be another causeway joining the island to the airport (top right) is actually the combined wakes of many boats and water taxis shuttling between them. Small, bright agricultural fields on well-drained soils (top left) contrast with the darker vegetation of back-bay swamps, where fishing is a popular pastime.
10. Earth at Night
In the years since the 2011 launch of the NASA-NOAA Suomi National Polar-orbiting Partnership (NPP) satellite, a research team led by Earth scientist Miguel Román of NASA’s Goddard Space Flight Center has been analyzing night lights data and developing new software and algorithms to make night lights imagery clearer, more accurate and readily available. They are now on the verge of providing daily, high-definition views of Earth at night, and are targeting the release of such data to the science community later this year.
Today they are releasing a new global composite map of night lights as observed in 2016, as well as a revised version of the 2012 map. The NASA group has examined the different ways that light is radiated, scattered and reflected by land, atmospheric and ocean surfaces. The principal challenge in nighttime satellite imaging is accounting for the phases of the moon, which constantly varies the amount of light shining on Earth, though in predictable ways. Likewise, seasonal vegetation, clouds, aerosols, snow and ice cover, and even faint atmospheric emissions (such as airglow and auroras) change the way light is observed in different parts of the world.