This image of the continental United States at night is a composite assembled from data acquired by the Suomi NPP satellite in April and October 2012. City and highway lights, gas flares, wildfires and a bit of reflected moonlight are visible. Click for a huge version. Credit: NASA Earth Observatory/NOAA NGDC
Wherever we go, our lights go with us. If we were more thoughtful about choosing the right type of lighting fixtures, it wouldn’t be such a problem, but we’re generally not. Photos taken late last year by the Suomi NPP satellite of Earth at night show the human footprint in blazing garlands of twinkling orange lights strung along coastlines, cities and highways.
While the sight is beautiful on one level, it’s a disturbing waste of good energy. Much of the electric lighting seen from space spills upward to brighten the night sky instead of being directed at the ground where it’s needed.
Comparison photos of the Bakken oil fields region in the year 2000 before active drilling and in 2012 with drilling going full bore. The photo at left was made by the Defense Meteorological Satellite Program; at right by Suomi NPP. Click to enlarge. Credit: NOAA, NASA
One of the most glaring examples of new light pollution shows up in the Bakken shale fields of northwestern North Dakota. Although one of the least densely-populated areas of the United States, the region has seen widespread oil-drilling and natural gas production in recent years. Most of the bright dots are lights associated with drilling equipment and temporary housing near drilling sites, but some are natural gas flares.
Closeup satellite image of lighting in the Bakken oil fields of northwestern North Dakota. Credit: NASA Earth Observatory/NOAA NGDC
Storage facilities and pipelines haven’t kept up with production, so the excess is burnt off in flares. This may sound like a bad idea, but it’s better than releasing it directly into the atmosphere. Methane is far nastier than carbon dioxide when it comes to the greenhouse effect.
Well-designed fixtures shield and direct light toward the ground. This example is from Manchester, UK.
While we all know lighting is necessary to carry on with tasks at night like driving home or picking up the kids at school, wisely-designed fixtures that contain the light in a box and direct it downward not only provide ample illumination, they also save energy, reduce glare and minimize light pollution of the night sky we all love.
Full moon on September 30, 2012 over the Persion Gulf. You can see both the lights of cities and highways as well as details of the landscape. Click to enlarge. Credit: NASA Earth Observatory/NOAA NGDC
Not all Earth lighting seen from orbit is manmade. Moonlight and aurora cast their natural hues across the planet’s skin, too. The Suomi NPP satellite captured a series of pictures showing dramatic changes in illumination of the Persian Gulf region between September 30 and October 15, 2012 when the moon waned from full to new phase.
With the moon at gibbous phase, the difference in lighting is quickly apparent. Click to enlarge. Credit: NASA Earth Observatory/NOAA NGDC
Notice that as the moon’s phase lessens, the cities become more obvious while the landscape darkens. To see all four panels showing the complete transition from full to new moon, click HERE.
The southern lights swirl over Antarctica in this satellite image taken on July 15, 2012. Look closely and you’ll see details in the ice shelf along the edge of ocean (top) lit up by the aurora. Credit: NASA Earth Observatory image by Jesse Allen and Robert Simmon
We’ll leave you with the choicest image of all – the aurora austrinus or southern lights, counterpart to the aurora borealis. Suomi NPP captured this image on July 15, 2012 over Antarctica’s Queen Maud Land and the Princess Ragnhild Coast. At the time the continent was shrouded in mid-winter darkness with a waning crescent moon providing very little illumination. LIght from the aurora was bright enough however to reveal icebergs and the coastline.
If you like your skies dark, here are some outdoor lighting tips on reducing light pollution around the house. For more on the issue, I highly recommend a visit to the International Dark-Sky Association’s Frequently Asked Questions.