till image from Hadley's simulation of the Starlink satellite constellation. Credit: Mark Hadley
Picture the space around Earth filled with tens of thousands of communications satellites. That scenario is slowly coming into being, and it has astronomers concerned. Now a group of astronomers have written a paper outlining their detailed concerns, and how all of these satellites could have a severe, negative impact on ground-based astronomy.
SpaceX has been garnering all the headlines when it comes to satellite constellations. Their Starlink system will eventually have thousands of tiny satellites working together to provide internet access, though only 242 of them have been deployed so far. But now another company is getting on the action: OneWeb.
The city of Denver, Colorado, as seen from space. Credit: NASA
When it comes to technology and the environment, it often seems like it’s “one step forward, two steps back.” Basically, sometimes the new and innovative technologies that are intended correct for one set of problems inevitably lead to new ones. This appears to be the case with the transition to solid-state lighting technology, aka. the “lighting revolution”.
Basically, as nations transition from traditional lights to the energy-saving Light-Emitting Diodes (LEDs), there is the potential for a rebound effect. According to an international study led by Christopher Kyba from the GFZ German Research Center for Geoscience, the widespread use of LED lights could mean more usage and more light pollution, thus counter-acting their economic and environmental benefits.
Photograph of Calgary, Alberta, Canada, taken from the International Space Station on Nov. 27th, 2015. Credit: NASA’s Earth Observatory/Kyba, GFZ
To put it simply, the cost-saving effects of LED lights make them attractive from a consumer standpoint. From an environmental standpoint, they are also attractive because they reduce our carbon footprint. Unfortunately, as more people are using them for residential, commercial and industrial purposes, overall energy consumption appears to be going up instead of down, leading to an increased environmental impact.
For the sake of their study, the team relied on satellite radiometer data calibrated for nightlights collected by the Visible/Infrared Imager Radiometer Suite (VIIRS), an instrument on the NOAA’s Suomi-NPP satellite that has been monitoring Earth since October of 2011. After examining data obtained between 2012 and 2016, the team noted a discernible increase in power consumption associated with LED use. As they explain in their study:
“[F]rom 2012 to 2016, Earth’s artificially lit outdoor area grew by 2.2% per year, with a total radiance growth of 1.8% per year. Continuously lit areas brightened at a rate of 2.2% per year. Large differences in national growth rates were observed, with lighting remaining stable or decreasing in only a few countries.”
This data is not consistent with energy reductions on a global scale, but rather an increase in light pollution. The increase corresponded to increases in the Gross Domestic Product (GDP) of the fastest-growing developing nations. Moreover, it was also found to be happening in developed nations. In all cases, increased power consumption and light pollution has natural consequences for plants, animals, and human well-being.
“The great hope was that LED lighting would lead to lower energy usage, but what we’re seeing is those savings being used for increased lighting. We’re not just seeing this in developing countries, but also in developed countries. For example, Britain is getting brighter. You now struggle to find anywhere in Europe with a natural night sky – without that sky glow we’re all familiar with.”
The team also compared the VIIRS data to photographs taken from the International Space Station (ISS) which showed that the Suomi-NPP satellite sometimes record a dimming of some cities. This is due to the fact that the sensor can’t pick up light at wavelengths below 500 nanometers (nm) – i.e. blue light. When cities replace orange lamps with white LEDs, they emit more radiation below 500 nm.
The effect of this is that cities that are at the same brightness or have experienced an increase in brightness may actually appear dimmer. In other words, even in cases where satellites are detecting less radiation coming from the surface, Earth’s night-time brightness is actually increasing. But before anyone gets to thinking that it’s all bad news, there is a ray of light (no pun!) to be found in this research.
In previous studies, Kyba has shown that light emissions per capita in the US are 3 to 5 times higher than that in Germany. As he indicated, this could be seen as a sign that prosperity and conservative light use can coexist:
“Other studies and the experience of cities like Tucson, Arizona, show that well designed LED lamps allow a two-third or more decrease of light emission without any noticeable effect for human perception. There is a potential for the solid state lighting revolution to save energy and reduce light pollution, but only if we don’t spend the savings on new light”.
Reducing humanity’s impact on Earth’s natural environment is challenging work; and in the end, many of the technologies we depend upon to reduce our footprint can have the opposite effect. However, if there’s one thing that can prevent this from continually happening, it’s research that helps us to identifies our bad habits (and fix them!)
The Milky Way and Aurora over Godafoss, waterfall of the gods, Iceland, by Stephane Vetter from France, the first place winner in Beauty of the Night Sky category, TWAN 2013 Earth & Sky Photo Contest.
The World at Night’s (TWAN) annual Earth & Sky photography contest showcases the stunning beauty of the night sky while highlighting the challenges of keeping our skies free from light pollution. TWAN has now announced the winners of this year’s contest, and the winning photos are simply breathtaking. This year’s theme of “Dark Skies Importance,” were judged in two categories: “Beauty Of The Night Sky” and “Against The Lights,” said Babak Tafreshi, the founder and director of TWAN,” and the winners were selected from submissions by photographers in about 45 countries.”
The selected images were judged to be those most effective in impressing the public on both how important and delicate the starry sky is as an affecting part of our nature, and also how bad the problem of light pollution has become.
Tafreshi added that “the amazing number of eye-catching entries from across the world tells how public attention to night sky is growing as well as interest to sky photography and we are very pleased if TWAN has a role on this increasing awareness.”
The overall contest winner and first prize in the Beauty Of The Night Sky category is our lead image, taken by Stephane Vetter of France, for his March 2013 panoramic photo “Sky Above Godafoss” of aurora and the Milky Way over the “Waterfall of the Gods” in Iceland.
See more winners and more information about the contest below:
The first prize in Against The Lights category goes to Andreas Max Böckle of Austria for his photo “Under the Hood” taken from overlooking the city of Salzburg in a moonlit night:
Stars over Salzburg, Austria by Andreas Max Böckle, the first winner in Against the Lights category in TWAN 2013 Earth & Sky Photo Contest.
David Malin, one of the judges and a world-known pioneer in scientific astrophotography said, “The 685 entries the judges examined (more than twice than the 2012 judged images) represent some of the best TWAN-style photographs ever gathered together in one place… I feel privileged to have seen so many beautiful images in such a short time!”
Click on the images here to see larger versions. You can see all the winners (and the great prizes they won) at the TWAN website, and this video highlights the winning photos:
‘Crossed Destinies,’ the Milky Way of Reunion Island, Indian Ocean by Luc Perro from France is the 2nd place winner in the Beauty of the Night Sky category in the TWAN 2013 Earth & Sky Photo contest.
Air glow (along with a lightning sprite) is visible in this image from the International Space Station. Credit: NASA
Light pollution is a two-way murky street. Not only have millions of people never seen the glow of our Milky Way in the night sky because of light pollution, but also when astronauts in the International Space Station look down at Earth, they see lights almost everywhere and a faint green or yellow air-glow — caused mostly by light pollution — hovers over the planet in a majority of the images they send back from space.
“Light pollution threatens the health of every living thing on Earth,” says a new planetarium-like video from the International Dark-Sky Association in collaboration with Loch Ness Productions, a U.S.-based full-dome planetarium show production company.
“Losing the Dark” illustrates problems caused by light pollution, with particular emphasis on how it affects night-sky visibility. But the video also offers simple solutions for mitigating light pollution, and reminds everyone it is not too late to save the starry sky.
Bob Parks, IDA Executive Director said, “Everyone who views ‘Losing the Dark’ can see how easy it is to make wise choices about outdoor lighting, and that together we can work to restore the night sky to its former glory.”
The video is narrated by astronomer Carolyn Collins Petersen, (whose voice you may recognize from past 365 Days of Astronomy podcasts), and the show is also available in full-dome versions for planetariums and science centers as a public service announcement.
“Planetariums champion the night sky already,” Collins Petersen said. “They tap into public awareness, so their audiences are a prime demographic for this message. The show gives planetarium professionals another tool to help educate the public about this critical issue. The HD version extends the message to more people through presentations by educators and dark-sky advocates.”
Where the dark skies are (and aren't). NASA image in the Public Domain courtesy of Marc Imhoff, Craig Mayhem & Robert Simon (NASA/GSFC) Christopher Elvidge(NOAA).
A good majority of modern Americans have never seen truly dark skies. I was fortunate to grow up in northern Maine in the 1970s with skies dark enough to see the summer Milky Way right from my doorstep. For most of the Eastern Seaboard of the United States, this is no longer the case. During the blackout brought on by Hurricane Sandy over the tri-state area in 2012 and after Hurricane Andrew hit Miami in 1992, many urbanites got to see an unfamiliar sight first hand; a dark night sky. There were even calls to 9/11 reporting fires on the horizon, which were in fact the Milky Way!
Do your skies look like this? (Photo by Author).
In just over two weeks time on March 10th, most of North America will “spring forward” once again to daylight savings time; three weeks afterwards on March 31st, the European Union will follow suit.
For astronomers, this means waiting until the later evening hours for total darkness and late start times for star parties. If it seems like we spend more of the year on daylight savings time, we in fact do; the Energy Policy Act of 2005 mandates that daylight savings for most of the U.S. (a majority of Arizona is a staunch hold out) now starts on the second Sunday of March and runs until the first Sunday of November, or about 65% of the year. But discussions of DST’s utility or anachronism aside, it puts just one more hurdle between astronomers and what they love: dark skies.
Observatory versus light pollution. (Photo by Author).
You can’t even see your hand in front of your face under truly dark skies. Such darkness is measured on what’s known as the Bortle Scale, with 1 being dark enough to notice air glow and phenomena like the Gegenschein, while 9 is a washed out inner-city night sky, with perhaps only the Moon and the brightest planets punching through the haze.
We once did a Bortle scale estimation while waiting for an airport shuttle on the Las Vegas strip; Vegas is arguably the most light-polluted locale on the planet. Jupiter, the Moon and the brightest stars of Orion could only be seen if you knew exactly where to look for them. In contrast, we’ve heard many service members remark about how splendid the sky looks from such deployed locations as Afghanistan.
A vanishing treasure; true dark skies. (Photo by Author).
The encroachment of civilization on wilderness areas also means that most school star parties and downtown observatories are restricted to bright targets, and serious deep sky observers must now drive several hours for a reasonably dark sky. Living just outside the Tampa/Saint Petersburg area in Florida, I can actually tell if it’s cloudy or clear at night just by how bright our bedroom appears with lights out. A cloudy sky reflects all the city lights back down, creating a “false dawn” that fills the room.
Dark sky sites are like secret fishing holes for backyard astronomers. Everyone knows of a few, some of which are even carefully hidden and discussed in hushed tones for fear of the light generating hordes which will descend upon them.
For dark skies in the Tampa Bay area, most observers head north to Chiefland along the Nature Coast about a two hour drive north. If you’ve got boat access, a truly dark sky locale can be had in the Dry Tortugas off of the Florida Keys to the south.
Dark Skies at Dunham Farms, Georgia (Photo by Author).
We recently visited such a hidden “dark sky island” in northern Georgia. Dunham Farms is a great old farmhouse Bed & Breakfast in Liberty County near Hinesville, Georgia. Despite how close as it is to Savanna, Dunham Farms sits in a “triangle of darkness,” a rarity along the Atlantic coast. We estimated the sky at a Bortle Scale of 2-3 while we were there doing nighttime astrophotography. Astronomy clubs in nearby Savanna also find dark sky requiem at nearby Tybee Pier, and further north, clubs such as the Midlands Astronomers based out of Melton Observatory in Columbia, South Carolina head to nearby Congaree Swamp.
And so it is along much of the U.S. East Coast, as observers must make to pilgrimage ever further inland in search of dark skies. Truth is, much of nighttime lighting is simply wasted energy headed skyward to illuminate the undersides of clouds and aircraft. Not only does this destroy our pristine night sky, but it’s also a threat to nocturnal wildlife and humans as well. Nigh-time lighting confuses migrating birds, often casuing them to fly into buildings. In 2009 the American Medical Association joined the fight against light pollution, citing it as a health risk. Light pollution effects our natural circadian rhythms, and studies show it may be linked to increased cancer rates as well. Turns out, our bodies need darkness.
But there is light (bad pun intended) at the end of the tunnel. Light pollution ordinances are now on the books in many municipalities. In 2001, the International Dark Sky Association recognized Flagstaff, Arizona as the first dark sky certified city. Increasingly, observatories around cities in Arizona such as Tucson and Flagstaff are being recognized as national scientific assets to be safeguarded.
Of course, legislation on the books is only as good as its enforcement. There are no “light pollution police” on the beat, and ordinances against “light trespass” are only put into practice when someone complains about it. We’ve found that frequently, inviting the neighbors over for a “backyard star party” can avoid having them install a World War II surplus anti-aircraft spotlight in their back yard to begin with… hey, that’s what your security light looks like to us!
And there’s nothing stopping hardware outlets from selling light fixtures that are illegal to install. A good fixture directs light downward where it’s needed. Lowes has recently launched its line of dark sky compliant outdoor lighting, and hey, if enough customers “vote with their wallets” more may follow suit. Its money saved in these cash strapped times, and a night sky gained!
Images of the Earth at night, taken from space are always a stunning sight, with cities, countries and whole continents glittering like jewels. But this beauty comes at a price. It used to be that anyone looking up on a clear night could see the Milky Way. As more and more of us are drawn to live in urban areas, our view of the sky is blotted out by the glare of our lights. Astronomers have known about the growing problem of light pollution for a long time. Now ecologists are becoming concerned that our artificial lights are affecting more than our view of the stars.
Researchers at the University of Exeter studying the ecological impact of artificial lighting have noted changes in distribution of invertebrate communities around artificial lighting which could affect the broader wildlife that depend on them. Simply put, it is easier for predators to find their prey, and harder for the prey to hide, in brightly lit areas. Streetlights may also be disrupting the natural rhythms of both fauna and flora, changing hibernation patterns and flowering times. It may also be affecting our own circadian rhythms as well as being a colossal waste of energy, an estimated $2.2 billion per year in the U.S. alone! On average, 30% of the light from a streetlight shines up and out.
Light pollution is a growing problem. Artificial lighting is increasing at the rate of 6% each year globally and is only going to get worse, as developing nations use more and more electric light. Since 1988 The International Dark-Sky Association has campaigned to protect and preserve the night environment and promote energy efficient options. Light what you need, when you need it, they say.
One of their projects is the International Dark Sky Places program which certify locations with exceptional nightscapes, either as communities, parks or reserves. The Kielder Forest and adjacent Northumberland national park covering 400 square miles in the UK is the latest area hoping to join the 12 dark sky reserves already recognised by the IDA worldwide. Such status can bring economic advantages too, astronomy is rapidly growing in popularity and with it astronomy based tourism, offering dark skies, observing opportunities and star parties and star camps.
Losing the stars can have a lasting impact on our culture too. Think of all the art, literature and music that have been inspired by the night sky. As we become increasingly disconnected from nature the stars are one of our most important links. There are many people today who have never been able to look up and see the Milky Way arching over their heads. Looking up at the stars allows us a vital opportunity to engage with the larger questions posed by the universe.
[/caption]Are you a fan of Citizen Science? Do you enjoy participating in projects that help researchers and possibly the environment?
GLOBE at Night is one such program! By taking naked-eye observations of the night sky in your area, you can help a world-wide effort to track the effects of light pollution.
Here’s all the info you need in order to participate in GLOBE at Night during 2012.
For starters, what is GLOBE at Night?
The GLOBE at Night program is an international citizen-science campaign designed to raise public awareness of the impact of light pollution on our night skies. GLOBE at Night aims to raise awareness by inviting citizen-scientists to measure their night sky brightness and submit their observations to a website from a computer or smart phone.
Light pollution not only threatens our “right to starlight”, but also affects energy consumption, wildlife and health. For the past six years, the GLOBE at Night campaign has been involving people in 115 countries.
Participating in GLOBE at Night requires only five easy steps:
Map of 2011 GLOBE at Night participation. Image Credit: GLOBE at Night / NOAO
You can also use the new web application data submission process. The GLOBE at Night website is easy to use, comprehensive and holds an abundance of background information. The database is usable for comparisons with a variety of other databases, like how light pollution affects the foraging habits of bats.
