Dark Sky Research Articles

The temporal analysis of light pollution in Turkey using VIIRS data

Artificial Light pollution (AL) in Turkey and in Turkish observatories between 2012--2020 have been studied using the archival data of Visible Infrared Imaging Radiometer Suite (VIIRS) instrument. The astroGIS database has been used in processing the data (https://www.astrogis.org) \cite{2020MNRAS.493.1204A}. The total energy released to space from Turkey increased by 80\% in 2019 with respect to 2012. In the span of the dataset, a steady and continuous increase has been observed throughout all cities of the country. On the other hand, Dark Sky Park locations, East and Southeast Anatolian regions and mostly rural areas around the cities kept their AL level constant. Four demographic parameters have been studied and they were found to be correlated very well with AL: Population ($R \simeq 0.90$); GDP ($R \simeq 0.87$); Total Power Consumption ($R \simeq 0.66$) and Outdoor Lightening ($R \simeq 0.67$). Contrary to countries acting to prevent AL increases, Turkey seems to be at the beginning of an era where AL will arithmetically increase throughout the country and enormous amount of energy will continuously escape to space and therefore will be wasted. Therefore, a preventive legislation, especially for invaluable astronomical site locations such as TURAG, TUG, DAG and \c{C}AAM where each is counted as a truly dark site due to their SQM values, has to be enacted in Turkey, in very near future.

Cover Image: Raedon

Raedon is about insomnia during the pandemic in the middle of December. The colours represent nocturnal hours as if they were the dark blue night sky with the northern lights out. Every students’ class is moved to remote access. Stay home advisories are still in place with social distancing. This causes some complications as there is a lot of “free” time in the comfort of our home. For me, it’s painting until 5 or 6 am in the morning. Then waking up just in time for WebEx class meetings, workout, homework, game, paint – repeat. 
 Awakening is about overcoming all the hardships the pandemic has brought. It is a part of my on-going series called The Void. The pandemic has shown me things I needed to deal with on a personal level. I hit rock bottom in my life and failed in so many ways during Covid-19. My life began to turn towards positive after fasting late summer of 2020. I’m fortunate to have a new perspective on my life and the future. I am grateful I get to finish my psychology degree and begin my Bachelor of Fine Arts. In other words, Awakening represents healing, strength and a clear focus for the future regardless of things going on outside of ourselves.

Light pollution colour changes at MHAONB, from distant town conversions to blue-rich LED lighting, implications for rural UK skies

The sky in the Malvern Hills Area of Outstanding Natural Beauty (MHAONB) has been monitored continually since 2012, when a dark sky survey of the area was carried out commissioned by Malvern Hills Conservators. Ever since then at F.C. Observatory Mathon, the sky brightness has been measured continually, in the last few years at minute intervals in all weathers. On the darkest of nights, a fisheye lensed camera was used at the same intervals. There is a trend in brightness distribution and colour changes on the sky, especially towards the horizon, with clearly separated bright sky domes. The sky quality meter (SQM) photometry data near zenith does not show any great change. In 2015, Malvern Hills Conservators commissioned the author for modelling of the effect on the MHAONB sky, of the ongoing blue rich LED re-lighting throughout Herefordshire.The SQM photometry shows the sky brightness are very weather dependant; and the camera shows colour changes from orange-pink to blue-rich LEDs. Besides the trend over recent years to blue white from orange, changes can occur over hours or even minutes, depending on cloud cover over individual towns on or beyond the horizon, and local humidity levels. It can vary from orange to blue and red. Clear skies can vary in overall colour from one night to another and brightness falls overnight. This is shown in isophotes and accurate profile curve fitting. The effect of 2020 lockdown is included. A measurement was made of the clear air back scatter ratio from a known luminance source which can be used to estimate the sky visibility degradation from any planned lighting scheme.For the rural UK, the Milky Way is only 20% contrast to background at zenith on the darkest nights, (MHAONB 21.10 mag.arcsec−2), doubling the road light level across Europe would make it invisible.

Is dark matter lighting up the sky with X-rays?

We know little about dark matter beyond its existence. That would change dramatically if hints of dark matter decaying to X-rays were confirmed. Indeed, this signal could be the evidence that finally helps unravel one of the greatest mysteries in physics and astronomy. Yet when searching for that signal in our own Milky Way, we found only dark skies. - submission by Nick Rodd

Who speaks for the night?

Efforts to control artificial light at night (ALAN) through public policies began in the late 1950s, yet light pollution continues to grow at a global average rate roughly twice that of population growth. The current global ALAN regulatory regime is clearly inadequate to solve the problem, and achieving meaningful light pollution reductions requires a new approach. This paper reviews the legal status quo, introduces the “Rights of Nature” doctrine, and advances the idea of nighttime darkness as a natural characteristic of sufficient inherent value to merit legal consideration in the Rights of Nature context. It concludes with a series of recommendations for ways forward, including the recognition of the intrinsic value of dark skies in the preambulatory language of legislation, formulating new policies in anticipation of broad adoption of Rights of Nature statutes, and advancing the significance of natural nighttime darkness in case law arguments.

Pandemics, Social Disruption, and Dark Skies: Apocalyptic Fictions and the end of Human Culture

Pandemics, Social Disruption, and Dark Skies: Apocalyptic Fictions and the end of Human Culture

Viral Vampires

Viral Vampires

More than Darkness Preservation

Enveloped in artificial light, many urban dwellers have never experienced real darkness. Seeing this as a loss, scholars and organizations have initiated discussions on light and darkness and advocated the preservation of the dark skies. This article aims to further this study by emphasizing the importance of the stars. Instead of studying lights, stars, and darkness ethnographically, the article examines the ideas of stars and darkness in Thierry Cohen’s photographs and two of Vincent van Gogh’s paintings. This article will suggest that the dark, star-filled skies represented in van Gogh’s paintings provide a visual blueprint of what the article calls the “star-lit cities,” which goes beyond a simple preservation of darkness, and may be significant in driving vital changes in combating the current environmental crises.

Protecting the Dark Skies of the Earth from Satellite Constellations Under International Space Law

Proceedings of the International Institute of Space Law is een online tijdschriftenplatform van Boom uitgevers Den Haag (Boom juridisch, Boom criminologie, Boom bestuurskunde en Eleven International publishing)

169 Investigating relationships between weather variables and dry matter intake of beef cattle in feedlot

Abstract Currently, the amount of feed delivered daily in feedlots is based on the previous day’s consumption and the estimated animal growth. Nevertheless, factors such as weather variables may influence feed consumption. The objective of this study was to evaluate the effect of weather on dry matter intake (DMI) in beef cattle finished in a commercial feedlot facility in South America. A total of 8.388 animals (Nellore and crossbreed Nellore x Angus) divided across 55 pens were evaluated from July 2018 to April 2019. The animals entered the feedlots with average body weight (BW) of 337 ± 28 kg and had a harvest BW of 517 ± 33 kg, with an average of 125 ± 25 days in feedlot. Daily feed consumption in each pen was estimated by subtracting any morning leftover feed from the total feed amount delivered on the previous day. Data on 16 weather variables for the farm location (latitude and longitude) was acquired using the Dark Sky API and processed in R. The weather variables were clustered via hierarchical cluster into groups given by: G1) humidity, cloud cover, and precipitation; G2) dew point, temperature (max, min, apparent max and apparent min), and day length; G3) atmospheric ozone and pressure; G4) UV index and visibility; G5) wind speed and gust; and G6) moon phase. Variables in G3 were positively correlated with DMI, while G2 and G4 presented negative correlations. The most important correlations were for day length (r = -0.74, P < 0.01), apparent max temperature (r = -0.65, P < 0.05), dew point (r = -0.65, P < 0.05), ozone (r = 0.62,P < 0.05), and pressure (r = 0.61, P < 0.05). In conclusion, several weather variables presented potential as candidate for the development of predictive models of DMI of beef cattle in feedlots.

The challenge of satellite megaconstellations

Earth’s exosphere is set to become increasingly crowded, with tens of thousands of commercial telecommunication satellites planned in the next few years. We need to ensure that technological and socio-economic advancements will not imperil scientific progress and humanity’s access to dark skies.

Dark skies and dark screens as a precondition for astronomy tourism and general well-being

Light pollution is one of the fastest-growing pollutants of the environment and considering the amount and diversity of negative consequences, it is a highly interdisciplinary subject. So far, most of the research about the negative influence of light pollution on human health was based on the disruption of the circadian clock, sleep deprivation, and other physical diseases. Together with artificial lighting, the rapid development of information and communication technology significantly contributed to the increased lighting levels in the indoor environment and at the same time influenced the perception of natural darkness as something unnatural and undesired. On the other hand, the same technologies can be a useful asset in the popularization of astronomy-related activities, thus promoting the necessity for dark skies preservation. This paper aims to emphasize the importance of dark skies and appropriate usage of ICTs in the nighttime hours for our psychological health and well-being in general and at the same time to propose astronomy tourism as a part of the sustainable tourism offer as a tool for fighting light pollution.

Daniel Deudney: Dark Skies: Space Expansionism, Planetary Geopolitics, and the Ends of Humanity

Daniel Deudney: Dark Skies: Space Expansionism, Planetary Geopolitics, and the Ends of Humanity

BVRCIC Observations and Analysis of the UV LEO-type Binary, the Pre-WUMa, V1023 Persei

Abstract V1023 Per is a polar spotted, but well-detached dwarf binary, very likely a Pre-WUMa eclipsing binary. It was observed on 11 nights in 2015 October, November, and December at Dark Sky Observatory in North Carolina with the 0.81 m reflector of Appalachian State University. The period behavior is complex and may be increasing with a cubic or quadratic ephemeris. Its odd light curves are of high amplitude but have no totality and reach maximum light just before and following the secondary eclipse, indicating that it has polar spots similar to UV Leo. The 28 yr orbital period study calls the attention of observers to further monitor this binary to understand the complex nature of the period evolution. Its presently fixed polar spot does indicate that it must have a strong magnetic field and that it is synchronously rotating. The BVR c I c simultaneous 2016 Wilson–Devinney program (W-D) solution gives fillouts of 68% and 75% for the primary and secondary components, respectively. The polar position of the spot, its radius (24°), and T-fact (0.75) indicate that a strong magnetic field is present. The small ΔT in the components (∼289 K) show that the stars are similar in spectral type despite them being well detached. The inclination is high, ∼85.°19 ± 0.°04, but there is not a total eclipse due to the high mass ratio (∼0.739 ± 0.001). Due to the low galactic position (longitude = 150.°390, latitude = −1.°023), its reddening is addressed. The primary components temperature is estimated to be 5250 ± 250 K.

Concentrations of dark haloes emerge from their merger histories

ABSTRACT The concentration parameter is a key characteristic of a dark matter halo that conveniently connects the halo’s present-day structure with its assembly history. Using ‘Dark Sky’, a suite of cosmological N-body simulations, we investigate how halo concentration evolves with time and emerges from the mass assembly history. We also explore the origin of the scatter in the relation between concentration and assembly history. We show that the evolution of halo concentration has two primary modes: (1) smooth increase due to pseudo-evolution; and (2) intense responses to physical merger events. Merger events induce lasting and substantial changes in halo structures, and we observe a universal response in the concentration parameter. We argue that merger events are a major contributor to the uncertainty in halo concentration at fixed halo mass and formation time. In fact, even haloes that are typically classified as having quiescent formation histories experience multiple minor mergers. These minor mergers drive small deviations from pseudo-evolution, which cause fluctuations in the concentration parameters and result in effectively irreducible scatter in the relation between concentration and assembly history. Hence, caution should be taken when using present-day halo concentration parameter as a proxy for the halo assembly history, especially if the recent merger history is unknown.

How are the Mediterranean islands polluted by artificial light at night?

The Mediterranean is considered as a World Biodiversity Hotspot because of the significant reservoir of endemics, which are threatened with destruction. Island ecosystems have special importance for biodiversity conservation in this region. However, most of them are under strong anthropogenic influences: recreational pressures, infrastructure development, fires etc. At the same time, new types of anthropogenic pressures have developed, one of which is the preponderance of artificial light at night (ALAN) and sky glow. This factor has not been perceived as dangerous for people and biodiversity until recently. However, the latest researches show the opposite conclusion: ALAN has a significant influence on reproduction, navigation, behavior, foraging, habitat selection, communication, and social interactions of all living organisms. Therefore, we have estimated the level of light pollution on the fifteen biggest islands of the Mediterranean using tools available from Google Earth Pro, and the New World Atlas of Artificial Sky Brightness in the form of a kmz layer created by Falchi et al. (2016). In addition, islands or their parts without ecological light pollution have been selected. The obtained results argue that light pollution is extremely high on these larger islands; there are no areas with zero-level of ecological light pollution. As well it has been found that the level of light pollution of these islands correlates with their human population density. Nevertheless, there are 49 small islands or their parts with “pristine” skies, and their total area is 118.67 km2. Also, four dark sky refugia (Western (313,593 km2), Adriatic (331 km2), Aegean (12,448 km2), and Eastern (841,195 km2)) were highlighted within the territory of the Mediterranean Sea. That is 46,61% of its total area. Special attention has been paid to protected areas of the region in the context of combating light pollution, as well as the potential for astro-tourism development. Recommendations for changing of the current ALAN-related situation are given.

Discursive constructions of night sky experiences: Imagination and imaginaries in national park visitor narratives

Communities and protected areas worldwide have initiated programs to protect and promote dark night skies. Yet, limited research has explored how and why night skies become of interest or meaningful to people. Because night skies are literally beyond human reach, we focus on how visitors to a U.S. national park imagine night skies and invoke imaginaries that make night skies meaningful. Drawing from interviews, we examine how visitors use symbolic language, narrative, and other discursive practices to develop the social, cultural, and spatial contexts of their night sky experiences. Findings inform our understanding of imagination and imaginaries in tourism and recreation research, while offering new approaches to night skies research.

In Search of Global Security: Everett C. Dolman’s Astropolitik and Daniel Deudney’s Dark Skies

ABSTRACT This essay is a conceptual and historical critique of the astropolitical proposals for global security in Everett C. Dolman’s Astropolitik: Classical Geopolitics in the Space Age (2002) and Daniel Deudney’s Dark Skies: Space Expansionism, Planetary Geopolitics, and the Ends of Humanity (2020). It focuses on the divergent views on space weaponization and world political order presented by the two authors. It reflects on previous critique of their work, examines strengths and weaknesses in their arguments, and highlights their shared common ground. The essay places their debate in a historical context by tracing the origins of the concept of space superiority and the Outer Space Treaty, and considers their ideas in relation to U.S. space policy in the 21st century. The critique concludes that the proposals advanced by both authors are problematic. In response, it suggests a rapprochement in the form of a United Nations Space Agency and Space Guard.

A case study of light pollution in France

France issued a decree to restrict and prohibit mainly outdoor lighting effective from January 1st, 2019. Effectiveness of this legislation has been evaluated in this study using GIS data which was first used in \cite{2020MNRAS.493.1204A} (so called astroGIS database - \url{astrogis.org}). A subset of Artificial Light layer of astroGIS database has been adapted for years between January 2012 and December 2019. During 2019, radiance of $1.9 \times 10^{9}$ W cm$^{-2}$ sr$^{-1}$ has been released into space. Annual light pollution in France decreased by 6\% after the enactment of artificial light legislation. France continue to have potential Dark Sky Park locations for example cities like Indre, Lot, Nievre and Creuse having the lowest light pollution values. A strong correlation between population and light pollution ($R\simeq 0.83$) has been observed. A similar but a weak correlation can also be observed for GDP ($R\simeq 0.28$). However, it is still too early to justify whether the improvements observed in the dataset are due to the enactment of the legislation or not.

Very important dark sky areas in Europe and the Caucasus region

ALAN (artificial light at night) can give, if done adequately, a lot of benefits for human society, but it affects reproduction, navigation, foraging, habitat selection, communication, trophic and social interactions of the biota in the same time. Taking into account dramatic increase in light pollution of the night sky and night environment during the past decades, the creation of refugia where natural habitats are not influenced by ALAN is very important. We selected promising territories without, or with a low impact of, ALAN for the development of a VIDA (Very Important Dark Area) Network in Europe and the Caucasus region. 54 VIDAs within the borders of 30 countries were chosen, located in different biogeographic regions, at different altitudes, and in juxtaposition with protected areas. Special attention has been paid to sea and ocean islands, non-polluted by ALAN, as well as to large parts of European Russia and Kazakhstan where there is still a low level of light pollution. These places might be a basis for the protection of biodiversity from the consequences of ALAN, and they can also serve as key education centers for increasing the awareness of the problem of light pollution of the sky at night. Due to the fact that light propagates far away in the atmosphere, the protection of VIDAs can be obtained only if a strong anti-light pollution action is enforced also in the surrounding areas, at least 100 km from the borders of the VIDAs.