The Earth at Night, Updated

NASA Earth Observatory images by Joshua Stevens, using Suomi NPP VIIRS data from Miguel Román, NASA’s Goddard Space Flight Center.

NASA has released updated global maps of the Earth at night. The so-called “black marble” maps show where human activity lights up the darkness. NASA’s page highlights some of the differences between the 2016 and 2012 versions of the map with before/after interactive sliders. John Nelson has tried something different: overlaying the 2016 map on the 2012 map with a clipping mask shows newly illuminated parts of the globe as dark patches.

John M. Nelson, “A Changing Earth at Night,” 2017.

New Atlas of Artificial Sky Brightness

artificial-sky

A new online atlas of artificial sky brightness is now available, based on updated light pollution data published last week. (There’s also a 3D globe version that may not work in all browsers.) Light pollution, as I’ve blogged before, is the bane of professional and amateur astronomers alike, obscuring fainter objects and interfering with observations, both naked-eye and through telescopes. As the article in Science Advances puts it, “This atlas shows that more than 80% of the world and more than 99% of the U.S. and European populations live under light-polluted skies. The Milky Way is hidden from more than one-third of humanity, including 60% of Europeans and nearly 80% of North Americans.” [Rumsey Map Center]

Previously: Light Pollution Maps; Testing Light Pollution Maps; Testing Light Pollution Maps Redux; Darker Than You Think.