Dark Sky Research Articles

Hybrid Photovoltaic and Gravity Energy Storage Integration for Smart Homes with Grid-Connected Management

This paper introduces a dynamic Smart Home Energy Management System (SHEMS) integrating a hybrid photovoltaic (PV) and gravity energy storage (GES) system aimed at minimizing environmental impacts and household energy consumption. The novel SHEMS features a one-week dynamic forecasting model that adapts to variable electricity prices, smart appliance schedules, solar output, and energy storage states. These results demonstrate that the system not only reduces household energy usage but also cuts electricity bills significantly, supplying power autonomously for up to 8.5 hours daily. By leveraging real-time data from the Dark Sky API on cloud cover and temperature, this model accurately predicts solar radiation and PV generation, aligning it with both grid and residential demands. The forecasting accuracy was assessed using Root Mean Square Error (RMSE) and Mean Absolute Percentage Error (MAPE), which improved to 12.55% and 4.91% respectively, from initial values of 22.46% for RMSE and 11.78% for MAPE. These advancements enhance grid stability and optimize energy storage during peak periods, reducing dependence on fossil fuels. The integration of innovative renewable energy technologies and sophisticated forecast modeling significantly boosts the system's efficiency, promoting the sustainable use of energy resources in line with environmental and economic goals.

CLOWN: The PASO Cloud Detection for Optimization of Automatic Optical Surveys

Orbiting space objects have become in the last decade a major nuisance impacting ground astronomy and orbiting space assets, from observatories to satellites and space stations. In particular with the rise of the satellite population in Low Earth Orbits, space objects are becoming an even bigger threat and a strong problem to astronomical observations. To tackle these threats, several coordinated surveillance networks composed of dedicated sensors (telescopes, radars, and laser ranging facilities) track and survey space objects, from debris to active satellites. As part of the European Space Surveillance & Tracking network, Portugal is developing the Pampilhosa da Serra Space Observatory, with both radio and optical telescopes dedicated to the Space Situational Awareness domain, deployed at a Dark Sky destination. To optimize telescope survey time, we developed CLOud Watcher at Night (CLOWN), an application interface that automatically monitors clouds in real time. This software can correctly trace cloud positions in the sky and provide accurate pointing information to the observation planning of the optical telescope to avoid cloudy areas. CLOWN only requires the use of an all-sky camera, which is already a norm in observatories with optical telescopes and can be used with any camera, including those for which no information about its model specification do exist. CLOWN does not require great computing power, and it does not require the installation of additional equipment. CLOWN results are very promising and confirm that the app can correctly identify clouds in a variety of different conditions and cloud types.

Gemini High-resolution Optical Spectrograph (GHOST) at Gemini South: Instrument Performance and Integration, First Science, and Next Steps

The Gemini South telescope is now equipped with a new high-resolution spectrograph called the Gemini High-resolution Optical SpecTrograph (GHOST). This instrument provides high-efficiency, high-resolution spectra covering 347–1060 nm in a single exposure of either one or two targets simultaneously, along with precision radial velocity spectroscopy utilizing an internal calibration source. It can operate at a spectral element resolving power of either 76,000 or 56,000, and can reach a signal-to-noise ratio of ∼5 in a 1 hr exposure on a V ∼ 20.8 mag target in median site seeing and dark skies (per resolution element). GHOST was installed on-site in 2022 June, and we report performance after full integration to queue operations in 2023 November, in addition to scientific results enabled by the integration observing runs. These results demonstrate the ability to observe a wide variety of bright and faint targets with high efficiency and precision. With GHOST, new avenues to explore high-resolution spectroscopy have opened up to the astronomical community. These are described, along with the planned and potential upgrades to the instrument.

Towards sustainable nocturnal environment management: a social-ecological-technical system analysis in Wallonia (Belgium)

This study examines the management of the nocturnal environment in Belgium’s Walloon region from a social-ecological-technical system perspective, aiming to enhance sustainability in nightscapes. To identify critical challenges and action priorities, we employ Political, Economic, Social, Technological, Environmental, and Legal analysis. Our research offers insights into the macro-environmental factors that organisations should prioritise when envisioning sustainable lighting and dark sky protection. Based on the outcomes of the Walloon case study and the recent literature, we determine the priorities that lead to shaping action plans and the research challenges to ensure a smooth transition towards more sustainable nightscapes. Key challenges emerge: a lack of awareness of light pollution, both for the authorities and citizens; a longstanding relationship between safety and lighting, with fears echoed in political discourse; and the lack of consideration of light pollution in legal, political and environmental agendas. To address these challenges, enhanced policies could be tailored to local contexts and improved to mitigate light pollution. Findings support a multidimensional strategy integrating public action with awareness campaigns, encouraging sustainable practices in management of nocturnal environments.

An Overview of Sky Brightness Surrounding Timau National Observatory (TNO), Indonesia

This study aims to analyze skylight conditions surrounding the newly constructed Timau National Observatory (TNO) in Kupang, Indonesia. The analysis was carried out with the primary reason of determining the initial conditions and surroundings of the area, thereby providing valuable information for future observers who will be using the facility. To achieve the stated aim, the sky brightness in the study area was measured in units of magnitudes per square arcsecond (mpsas) at a 20-kilometer radius. Furthermore, numerous observations were conducted at 32 distinct observation points using Sky Quality Meter (SQM) LU-DL (SQM-LU-DL), which was directed towards the zenith. The results obtained from these observations were subsequently analyzed using Surfer software with the primary aim of determining sky brightness in the study area. The analysis showed variations in sky quality in a 20 km radius, ranging from 21.64 to 20.37 magnitudes per square arcsecond (mpsas). The measurements showed that sky quality fell between the categories of great dark and semi-suburban transitional skies. However, it was important to comprehend that recent investigations had identified bright areas surrounding the observatory area, capable of diminishing the visual quality of sky if left unaddressed.

MONITORING OF LIGHT POLLUTION IN THE TRANSCARPATHIAN REGION

Light pollution first gained attention when people realized they could no longer see the night sky as they once did due to excess visible and ultraviolet light from cities. However, in recent years, it has become clear that artificial night lighting worries not only astronomers. Studies have shown that artificial night lighting harms a variety of animals. To preserve the natural darkness of the sky in the world, parks of the dark (or starry) sky are created, which are the areas of a unique natural environment that protect the natural night darkness from pollution by artificial light. They are the equivalent of nature reserves — territories with exceptional natural value. They perform protective functions for the darkest corners of our planet, where the night environment is not dis- turbed by artificial light. These parks perform not only ecological but also educational functions. Darkness protection is slowly being incorporated into existing conservation areas such as national parks. Darkness is a natural resource that needs protection. In 2016, Transcarpathian Dark Sky Park was created. For its registration and entry into the International Association of Dark Sky Parks, the brightness of the night sky was measured in different places in this park to determine the state of light pollution in this area. The results of the measurements fully satisfied the requirements for dark sky parks. In all places of the Transcarpath- ian Dark Sky Park where we performed measurements, the average value of the background of the night sky was ~21.50 mag/ arcsec 2 . In 2021, an application for registration of Transcarpathian Dark Sky Park in the International Association of Dark Sky Parks was accepted. Research into the state of light pollution on the outskirts of the Dark Sky Park is also ongoing, namely at two optical observation stations — Uzhhorod and Derenivka. The results of changes in the background of the night sky in these places over a 40-year time interval are presented.

Fisheye Night Sky Imager: A Calibrated Tool to Measure Night Sky Brightness

The Night Skies Team of the U.S. National Park Service (NPS) has developed a new camera system equipped with a fisheye lens to measure night sky brightness. This NPS Fisheye Night Sky Imager comprises a back-illuminated Sony IMX455 CMOS sensor housed in the ZWO ASI6200MM camera, a Johnson V filter, and a Sigma 8 mm F3.5 fisheye lens. All of the components are commercially available. The fisheye lens allows us to capture the entire sky in a single frame. The wide-angle view also introduces calibration challenges. To address this, we have customized tools and devised innovative methods for calibrating the system, including flat-field correction, pixel scale determination, and field of view characterization. Additionally, we use standard stars for precise positional and photometric calibration. Furthermore, we create an open-source Python pipeline to process these fisheye images and leverage Git and GitHub for source code version control and distribution. The resulting images provide a positionally and brightness-calibrated fisheye view of the night sky, with a photometric calibration uncertainty of 0.12 mag. When comparing our Fisheye Night Sky Imager measurements to images taken with other calibrated systems, we reliably achieve consistent results under both dark and bright skies. Our Fisheye Night Sky Imager not only enables rapid assessment of sky quality but also supports the feasibility of establishing permanent monitoring locations. Recognizing that the natural dark sky is a critical element for natural, cultural, educational, and visitor experiences, this new camera system enhances our ability to assess resource conditions and fulfill the NPS mission of conserving resources unimpaired for the enjoyment of this and future generations.

Investigating potential Dark Sky Parks in Balkans

Investigating potential Dark Sky Parks in Balkans

Projection helps to improve visual impact: On a dark or foggy day

Driving is a highly visually demanding activity. Different driving conditions have different effects on drivers, so to understand the effects of driving vision on drivers, this paper directly investigates the role of central and peripheral vision in different scenarios and tests whether projection training improves driving behavior. We use a VR device to selectively present information in the central and peripheral parts of the field of view to achieve these goals. In Experiment 1, we compare drivers’ performance with and without experience when driving through four different visual conditions under dark and foggy skies. Participants’ visual search behavior and driving behavior activities were recorded simultaneously. Experiment 2 determined whether training with a circular projection of three colors improved the driver’s behavior. The results showed that (1) central vision is critical to the driver, and the importance of peripheral vision can be directly measured using the VR device; (2) a clear middle and blurred peripheral vision not only improves driver behavior in foggy weather but also helps to improve attention and driving ability; and (3) the color projection training indicated that the green projection was more effective than the others and that it significantly improved (4) Novice drivers collected visual information mainly from their central vision and were less able to drive than veterans, but green projection improved their driving ability and reduced collisions. Most importantly, the study results provide a new visual training paradigm that can improve driver behavior on dark and foggy days, especially for female novices.

A Review of the Characteristics of Light Pollution: Assessment Technique, Policy, and Legislation

Light pollution from the use of artificial lighting poses significant impacts on human health, traffic safety, ecological environment, astronomy, and energy use. The advancement of characteristics of light pollution assessment technology has played a significant role in shaping prevention and control policies, thereby enabling measures, such as environmental standards and legislation and product procurement guidelines, but considerable variation in the definition, control strategies, and regulatory frameworks remains. Therefore, there is a need to review the characteristics of light pollution, including the assessment technique, policy, and legislation. Through the literature review, it can be found that technical standards are required to prevent light pollution. For example, light pollution is decreased by 6% in France through the legislation of artificial light. Key approaches are suggested to control global light pollution, including implementing ambient brightness zoning, regulating lighting product usage, and establishing dark sky reserves. Technology and policy should be integrated. The precise data coming from satellite imagery, drones, and balloons could provide guidance when making the policies.

DIY Photometer Performance Test in Determining Morning Twilight

Abstract Do-It-Yourself (DIY) Sky Quality Meter (SQM) known as D.I.Y – CJ’01 Photometer has been successfully built and tested. Using SQM as a calibrated portable photometer is a hot topic of astronomical research regarding night sky brightness measurement. The output data obtained by the photometer is in unit of magnitude per square arc second (mag/sq arcsecond ∼ mpsas) value with a maximum value of 21.7 mpsas as a quantization of the representation of a very dark sky with the presence of natural airglow. The sky brightness then gradually increases with values up to 16.7 mpsas, which is when the sky is brighter due to the presence of artificial airglow from outdoor artificial lighting such as in big cities. This research aims to determine the D.I.Y – CJ’01 Photometer performance in measuring the sky brightness of morning twilight. The research method used in this work is an experiment with data collection from D.I.Y - CJ’01 Photometer and SQM Unihedron gathered from two locations in Cimahi and Bandung. Data processing shows that the D.I.Y - CJ’01 Photometer mimics the performance of SQM Unihedron, with the the smallest difference for the value of the solar depression angle in morning twilight measurements is 0.06%.

Cosmological Inference from within the Peculiar Local Universe

The existence of ‘peculiar’ velocities due to the formation of cosmic structure marks a point of discord between the real universe and the usually assumed Friedmann–Lemaítre–Robertson–Walker metric, which accomodates only the smooth Hubble expansion on large scales. In the standard ΛCDM model framework, Type Ia supernovae data are routinely “corrected” for the peculiar velocities of both the observer and the supernova host galaxies relative to the cosmic rest frame, in order to infer evidence for acceleration of the expansion rate from their Hubble diagram. However, observations indicate a strong, coherent local bulk flow that continues outward without decaying out to a redshift z≳0.1, contrary to the ΛCDM expectation. By querying the halo catalogue of the Dark Sky Hubble-volume N-body simulation, we find that an observer placed in an unusual environment like our local universe should see correlations between supernovae in the JLA catalogue that are 2–8 times stronger than seen by a typical or Copernican observer. This accounts for our finding that peculiar velocity corrections have a large impact on the value of the cosmological constant inferred from supernova data. We also demonstrate that local universe-like observers will infer a downward biased value of the clustering parameter S8 from comparing the density and velocity fields. More realistic modelling of the peculiar local universe is thus essential for correctly interpreting cosmological data.

Global astrotourism initiatives and the applicability of their strengths, weaknesses, opportunities and threats to astrotourism in South African National Parks

South African National Parks (SANParks) must generate operational income through innovative resource development. Astrotourism was identified as a potentially suitable income-generating activity. Various astrotourism initiatives are operational globally. However, their applicability within the South African context is unknown. The research evaluated successful global astrotourism initiatives to determine how these examples can be applicable to SANParks. Sixty-two global astrotourism initiatives were evaluated and 42 in-depth stakeholder interviews were conducted. Thematical data analysis was followed by a strengths, weaknesses, opportunities and threats (SWOT) analysis. The research makes a meaningful contribution by highlighting important concepts for consideration in support of viable astrotourism development in SANParks. Elements requiring consideration to provide tourists with quality experiences include appropriate locations for astrotourism activities, mitigation of light pollution, climate, seasonality, need for community engagement, well-trained presenters, carefully planned programmes and development of suitable management policies to protect dark skies, allowing for variation within each park's unique situation.

Satellite Visibility During the 2024 April Total Eclipse

On 2024 April 8, tens of millions of people across North America will be able to view a total solar eclipse. Such astronomical events have been important throughout history, but with nearly 10,000 satellites in orbit, we question whether total eclipses will now reveal a sky full of satellites, fundamentally changing this experience for humanity. Using the current population of Starlink satellites, we find that the brightest satellites would be naked-eye visible in dark skies, but the high sky brightness during totality will make them undetectable to the unaided eye. Our model does not take into account the effects of chance reflections from large, flat surfaces like solar panels, which we expect will cause glints and flares that could be visible from large satellites and abandoned rocket bodies. Time-lapse all-sky imaging might reveal satellites during the eclipse.

The ArgusSpec Prototype: Autonomous Spectroscopic Follow-up of Flares Detected by Large Array Telescopes

ArgusSpec is a prototype autonomous spectroscopic follow-up instrument designed to characterize flares detected by the Argus Pathfinder telescope array by taking short exposure (30 s) broadband spectra (370–750 nm) at low resolutions (R ∼ 150 at 500 nm). The instrument is built from consumer off-the-shelf astronomical equipment, assembled inside a shipping container, and deployed alongside the Argus Pathfinder at a dark sky observing site in Western North Carolina. In this paper, we describe the hardware design, system electronics, custom control software suite, automated target acquisition procedure, and data reduction pipeline. We present initial on-sky test data used to evaluate system performance and show a series of spectra taken of a small flare from AD Leonis. The $35k prototype ArgusSpec was designed, built, and deployed in under a year, largely from existing parts, and has been operating on-sky since 2023 March. With current hardware and software, the system is capable of receiving an observation, slewing, performing autonomous slit acquisition, and beginning data acquisition within an average of 32 s. With Argus Pathfinder’s 1 s cadence survey reporting alerts of rising sources within 2 s of onset, ArgusSpec can reach new targets well within a minute of the start of the event. As built, ArgusSpec can observe targets down to a 20σ limiting magnitude of m V ≈ 13 at 30 s cadence with an optical resolution of R ∼ 150 (at 500 nm). With automated rapid acquisition demonstrated, later hardware upgrades will be based on a clean-sheet optical design, solving many issues in the current system, significantly improving the limiting magnitude, and potentially enabling deep spectroscopy by the coaddition of data from an array of ArgusSpec systems. The primary science driver behind ArgusSpec is the characterization of the blackbody evolution of flares from nearby M-dwarfs. Large flares emitted by these stars could have significant impacts on the potential habitability of any orbiting exoplanets, but our current understanding of these events is in large part built on observations from a handful of active stars. ArgusSpec will characterize large numbers of flares from across the night sky, building a spectroscopic library of the most extreme events from a wide variety of stellar masses and ages.

Perceptions of Personal Lighting Devices and Associated Behaviors: Shifting Personal Norms and Behavior for Broader Conservation Actions

Anthropogenic light impacts both wildlife and human well-being, and national parks are some of the only remaining large swaths of land where natural dark skies remain. Over the past two decades, a significant amount of science has contributed both to our understanding of these impacts and to engineering advances to reduce negative lighting effects. This has resulted in changes to lighting infrastructure in some national parks, and growth in Dark Sky Certification for many protected areas globally. To date, changing infrastructure, such as street and parking lot lighting, to less intrusive hues and intensities or removing lights altogether have been some of the sustainable changes made in these areas. This study advances our understanding of lighting issues by examining national park visitors’ perceptions of personal lighting use (e.g., headlamps). Specifically, this study explores camper and mountaineer perceptions of personal lighting devices and their impact on social and ecological systems in Grand Teton National Park, USA. During peak visitation in the summer of 2023, 17 mountaineer interviews and 16 general camper interviews took place in the park at night. Results indicate that campers and mountaineers are largely unaware of anthropogenic light impacts on wildlife and humans. However, once informed, they are willing to change their behaviors and reduce the use of personal lighting devices and use more wildlife-friendly lighting with amber or red settings (which, to date, are just emerging and available for general consumers by several companies). These results provide insights for developing educational strategies and personal lighting engineering designs that will ultimately lead to more sustainable normative shifts capable of reducing anthropogenic lighting impacts in parks and beyond.

Visitor outcomes from dark sky tourism: a case study of the Jasper Dark Sky Festival

ABSTRACT Dark sky tourism is a growing, but under-studied sector of ecotourism. While some research has examined the economic impacts, regional sustainability, and management of dark sky tourism, researchers know little about tourist experiences and outcomes. This study seeks to determine visitor outcomes (satisfaction, learning, attitudes, and behavior changes) among participants at the Jasper Dark Sky Festival in Alberta, Canada. Visitors were middle-aged, balanced between genders, traveled an average of 430 km, and were primarily urban-based. Most were first-time visitors, were present 2 or more days, and attended over 5 festival events. Respondents reported high satisfaction levels, due to the low cost and diversity of events, and welcoming nature of the community, presenters, and volunteers. Respondents reported many areas of learning, particularly about the night sky and night animals. Respondents had very positive attitudes about protecting dark skies, but only 42% planned to change any behaviors to protect dark skies. Study results will help festival organizers design dark sky tourism events to optimize visitor outcomes. In particular, festival organizers can address some barriers to behavioral change, such as stressing the value of dark skies and providing information about how to reduce light pollution.

Evaluating the benefits of dark and quiet skies in an age of satellite mega-constellations

In an age of proliferating satellite constellations and congested Earth orbits, what is the status and value of dark and quiet skies? Satellite mega-constellations such as Starlink are illuminating the night sky with unnatural light and making astronomical observations—both professional and recreational—increasingly difficult. Radio frequency interference (RFI) from these constellations also adds obtrusive “noise,” impacting sensitive astronomical observations in the radio portion of the electromagnetic spectrum. Scientists predict that the growing commercial space sector will add more than 100,000 satellites to Earth's orbit by the end of the decade, raising concerns from numerous scientists as to the future of dark skies. Astronomy, in particular, is inevitably affected by the impending disappearance of dark and quiet skies, which are necessary conditions for many aspects of scientific research. This topic has also gained attention, at both the international level and national level, within the United States. Nonetheless, contributions to the conversation of mitigating light/noise pollution predominantly focus on the likely adverse effects of artificial sky brightening from satellites. A holistic discussion is also warranted on the benefits of existing night skies and their significance for society.This paper addresses the positive value of dark skies and the significance of protecting astronomy through current governing and analogous frameworks. First, this paper evaluates dark skies’ application under existing international and national law and policy, highlighting lacunae in governance and outlining convoluted issues for Earth-based science (astronomy) versus the lawful use of space (satellites). U.S. space law is used as a case study given the extensive history of the United States in space, comprehensive U.S. space political infrastructures, and the burgeoning domestic satellite mega-constellation industry. Second, relevant ethical values are identified to clarify inherent moral considerations that can guide policymaking and serve to establish practical measures and approaches to balance the conflicting interests of astronomers and satellite operators. Significantly, this paper contributes to the topic by explaining how the advent of technological change creates new conflicts on Earth and expounds on how and why these issues are lacking or are inadequate under current international frameworks. Moreover, this work explores key ethical values on this topic for informing public policy on dark and quiet skies and highlights some mechanisms for resolving these conflicts. In conclusion, the recession of dark skies is already occurring, and the likely impacts require transparency, good will, and interdisciplinary compromise between scientists, policymakers, and the space industry.

Alternative Forms of Tourism: A Comparative Study of Website Effectiveness in Promoting UNESCO Global Geoparks and International Dark Sky Parks

In the digital age, effective website promotion plays a pivotal role in attracting visitors to alternative forms of tourism. This study examines the websites of 177 UNESCO Global Geoparks and 190 International Dark Sky Parks, employing specific evaluation criteria essential for enhancing the promotion of alternative tourism forms such as geotourism and astronomical tourism. Our findings reveal that geopark websites adeptly promote geotourism through a diverse array of digital tools, with the potential for minor enhancements. In contrast, the majority of dark sky park websites exhibit limited visibility in the promotion of astronomical tourism. These identified criteria and results serve as crucial benchmarks for optimizing the websites of UNESCO Global Geoparks and International Dark Sky Parks, thus ensuring the comprehensive fulfillment of established promotional standards for alternative tourism destinations.

Toward a Spectrophotometric Characterization of the Chilean Night Sky. A First Quantitative Assessment of ALAN across the Coquimbo Region

Light pollution is recognized as a global issue that, like other forms of anthropogenic pollution, has a significant impact on ecosystems and adverse effects on living organisms. Plentiful evidence suggests that it has been increasing at an unprecedented rate at all spatial scales. Chile—which, thanks to its unique environmental conditions, has become one of the most prominent astronomical hubs of the world—seems to be no exception. In this paper we present the results of the first observing campaign aimed at quantifying the effects of artificial lights at night on the brightness and colors of the Chilean sky. Through the analysis of photometrically calibrated all-sky images captured at four representative sites with an increasing degree of anthropization, and the comparison with state-of-the-art numerical models, we show that significant levels of light pollution have already altered the appearance of the natural sky even in remote areas. Our observations reveal that the light pollution level recorded in a small town of the Coquimbo Region is comparable with that of Flagstaff, Arizona, a ten times larger Dark Sky city, and that a mid-size urban area that is a gateway to the Atacama Desert displays photometric indicators of night sky quality that are typical of the most densely populated regions of Europe. Our results suggest that there is still much to be done in Chile to keep light pollution under control and thus preserve the darkness of its night sky—a natural and cultural heritage that it is our responsibility to protect.