Space and astronomy news
There’s no question that light pollution is a growing problem. Thankfully many scientists and advocates are working for change. And you can be a part of that change with a simple app that you can download to catalog the street lights in your neighborhood.
Continue reading “You Can Help Measure Light Pollution with Your Phone”
The night sky is a part of humanity’s natural heritage. Gazing up at the heavens is a unifying act, performed by almost every human that’s ever lived. Haven’t you looked up at the night sky and felt it ignite your sense of wonder?
But you can’t see much night sky in a modern city. And the majority of humans live in cities now. How can we regain our heritage? Can quiet contemplation make a comeback?
Continue reading “How Could we Light our Cities and Still See the Night Sky?”
Ah, the majestic dung beetle. The pinnacle of evolution. In all seriousness, these little critters are incredibly sophisticated navigators who have, for millennia, used the night sky to guide them about their business. But light pollution is making their lives more difficult by limiting their ability to navigate by the stars. Other nocturnal creatures, including some birds and moths, may be facing similar challenges.
Continue reading “Light Pollution is Making it Harder for Animals to Find Their Way at Night”
“The best laid plans of mice and men often go awry” – this famous paraphrase of Scottish poet Robert Burns sometimes sums up human ingenuity. That is exactly what happened when a county in Washington State decided to replace all of its county-owned streetlights with LEDs at least partially in an effort to combat light pollution. New research shows that they actually made the light pollution worse.
Continue reading “The Streetlights in an Entire County Were Swapped to LEDs. Light Pollution got Worse”
Being able to look up at a clear, dark sky is becoming more and more rare in the rich world. Authors, artists, and even scientists have started to express concern about what our lack of daily exposure to a dark night time sky might mean for our psyche and our sense of place in the universe. Now a team has collected photometric data at 44 sites around the world in an attempt to quantify how dark the night sky actually is at different places on the globe. So where was the darkest place surveyed? The Canary Islands.
Continue reading “Astronomers Measure the Background Brightness of the Night sky Across the World. Canary Islands are the Darkest in the Survey”
New research has found that as the number of satellites in Earth orbit continues to increase, their accumulated light pollution will brighten the night sky – making it much harder to do fundamental astronomy.
Continue reading “Satellites Have Brightened the Skies by About 10% Across the Entire Planet”
Light pollution is the arch nemesis of astronomy, spoiling both the enjoyment of the night sky and the professional study of our universe. For years we’ve assumed that streetlights are the main culprit behind light pollution, but a recent study has shown that streetlights contribute no more than 20% of all the pollution, and if we want to solve this vexing astronomical problem, we have to think harder.
Continue reading “Most light pollution isn’t coming from streetlights”
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.
Continue reading “Astronomers Have Some Serious Concerns About Starlink and Other Satellite Constellations”
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.
Continue reading “Here Comes the Next Satellite Constellation. OneWeb Launches 34 Satellites on Thursday”
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.
The study, titled “Artificially Lit Surface of Earth at Night Increasing in Radiance and Extent“, recently appeared in the journal Science Advances. Led by Christopher C. M. Kyba, the team also included members from the Leibniz Institute of Freshwater Ecology and Inland Fisheries, the Instituto de Astrofísica de Andalucía (CSIS), the Complutense University of Madrid, the University of Colorado, the University of Exeter, and the National Oceanic and Atmospheric Administration (NOAA).
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.
As Kevin Gaston – a professor from the Environment and Sustainability Institute at the University of Exeter and a co-author on the study – explained in a University of Exeter press release:
“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!)
Further Reading: Eureka Alert!, University of Exeter, Science Advances