Results of a survey assessing the impact on respondents and their students from the worldwide, citizen-science light pollution campaign called GLOBE at Night and the accompanying environmental-astronomy-based curricula called Dark Skies Rangers are presented.

The GLOBE at Night citizen-science campaign was introduced in China in 2010. Observations and works made by students are presented. The students were guided to participate in this meaningful international activity by 1) taking light pollution observations of the night sky at different locations, 2) becoming aware of the severity of the effects of light pollution, and 3) making the whole society aware of the importance to save energy by reducing light pollution.

Once data from a citizen-science program on light pollution is verified, what research projects, on-line analytical tools and tutorials should be developed, and what ways can results and acknowledgements be provided to the public? These and other questions are explored.

To battle light pollution issues, influence the market so that customers request only good lighting. An important factor in doing this is to convince decision makers that light pollution is something the whole society cares about. This article gives an overview of an existing campaign that does this and emphasizes some important factors to consider in your campaign.

The Aoraki Mackenzie International Dark Sky Reserve is a new reserve created in 2012 by the International Dark-Sky Association in the central South Island of New Zealand, and covers over 4300 square kilometres around Mt John University Observatory. It is the first such reserve to be recognized at gold tier level and is the largest dark sky reserve in the world. Astro-tourism in the new reserve will be a prominent activity in the coming years.

The Astro Izery project is carried by several institutions from Poland and Czech Republic. Its aim is to educate and inform tourists, who visit the Izery Mountains, about astronomy and light pollution. The project consists of two activities: permanent (sundials, planetary path etc.) and periodic (meetings, workshops). After five years the project is in good health and will gain more elements in next years.

The upward emission direction of artificial light from cities is unknown, and is the most important systematic uncertainty in simulations of skyglow. We present a technique for measuring the emission for zenith angles up to 70°.

The NIXNOX project, sponsored by the Spanish Astronomical Society, is a Pro-Am collaboration with the aim of finding sites with dark skies. All sky data of the night sky brightness is being obtained by amateur astronomers with Sky Quality Meter (SQM) photometers. We are not looking for remote locations because the places should be easily accessible by people with children. Our goal is to motivate citizens to observe the night sky. NIXNOX will provide information to answer the question: where can I go to observe the stars with my family?

The Night Sky Monitoring Network is a project that aims to study the extent, distribution, and properties of the light pollution condition in the populous metropolis of Hong Kong. Continuous measurements of the Night Sky Brightness (NSB) at strategically chosen locations that cover a wide range of population density and land usage were made, with over 2.5 million NSB readings collected in 18 months up to June 2012. Results from the project are presented, with focus on the contrast between the urban and rural night sky profiles, and light pollution contributions from artificial lightings. This project is supported by the Environment and Conservation Fund of the Hong Kong SAR government (ECF 10/2009, ECF 1/2007).

We have deployed a network of autonomous photometers that continuously measures the night sky brightness in the visual region at two sky positions simultaneously, typically near the zenith and the second at an elevation angle of 20 degrees. The Photometers are calibrated as a network to better than 5.

A standard format for recording skyglow measurements is needed to allow for effective data exchange. A proposal for such a format was discussed at the IAU Symposium.

In this paper, we suggest to use a sky radiance model which accounts for heterogeneous distribution of light fixtures, their photometry, the ground reflectance and topography, to infer the point to point contribution of Canary Islands to the artificial sky radiance at Observatorio del Teide (Tenerife) and Observatorio Roque de los Muchachos (La Palma). In-situ hyperspectral sky radiance measurements, acquired on site in 2010, have been used to calibrate the model and to evaluate its inherent error. We aim to identify and characterize zones at which any lighting level increase or decrease may have a larger impact on light pollution at both European Northern Observatory sites, and then help to control and/or reduce their light pollution levels. This innovative methodology, can then be seen as a high level decision tool to help local authorities to restrict or reduce light pollution with the objective of protecting research class astronomical sites.

The Cherenkov Telescope Array (CTA) is an international project for which more than 1000 scientists from 27 countries work together to install two observatories, one in the southern hemisphere and the other in the north, to study gamma-ray radiation. Argentina is a candidate site for one of the observatories, and to characterize proposed sites, one must study the sky background brightness. This critical point must be studied with care. Nearest cities can be a decisive factor in determining where to locate an observatory in our times.

Over the last two decades, La Serena's population has increased by about 70 percent. A site description of the AURA Observatory in Chile as a “Window to the Universe“ is now available on the recently-launched UNESCO-IAU Astronomical Heritage Web Portal, www.astronomicalheritage.net This can serve as an example of possible material for the Chilean authorities, should they wish to propose the dark skies over much of northern Chile for protection as a World Scientific Heritage site. Some of the steps involved are discussed briefly here.

With outdoor lighting ordinances in Arizona first in place around observatories in 1958 and 1972, then throughout the state since 1986, Arizonans have extensive experience working with communities and businesses to preserve our dark skies. Though communities are committed to the astronomy sector in our state, astronomers must collaborate with other stakeholders to implement solutions. Ongoing education and public outreach is necessary to enable ordinance updates as technology changes. Despite significant population increases, sky brightness measurements over the last 20 years show that ordinance updates are worth our efforts as we seek to maintain high quality skies around our observatories. Collaborations are being forged and actions taken to promote astronomy for the longer term in Arizona.

Before 1950 there are two observatories, Shanghai and Purple Mountain Astronomical Observatories (SHAO and PMO), and two observing stations, Qingdao and Kunming stations in China. With the requirements of astronomical research, two observatories, Beijing and Shaanxi Astronomical Observatories (BAO and SXAO) and two artificial satellite stations, Urumqi and Changchun, were established about 1960. Based on the current management, now there are 4 observatories, SHAO, PMO, NAOC(National Astronomical Observatories), which was grouped from BAO, YNAO and 2 others, as well as XAO (Xinjiang Astronomical Observatory). The optical 1-2 m class telescopes are being operated at former four observatories. SXAO is changed as National Time Service Center. Because of city expansion as well as the traveling and economic developments, these observatories are suffered severe light pollution. For example, Zo Ce is located at the suburb of Shanghai city. A 40 cm double astrograph was installed in 1900 and a 1.56 m optical reflector have been operated since November 1987. In 1994 the seeing is better than 1 and the night sky brightness in V is about 19 mag/arcsec2, stars fainter than 20 mag with CCD are visibles. In 2007 a large playground was built in Zô Cè area. The light pollution is severe gradually. The night sky brightness has been increased to 15.8 mag/arcsec2. The other observatories have similar situation. New site surveys and found new stations to solve the problem. Except the solar and radio stations of each Astronomical Observatory, now there are 3 optical observing sites at PMO (Hong-He, Xu-Yi and Yaoan), 2 at SHAO (Zô Cè and Tian Huang Ping) and 2 at YNAO (Kunming and Gao-Mei-Gu) as well as 1 optical observing site at BAO (Xing-Long). The best observing site is Gao-Mei-Gu, which is selected as the optical observing site of YNAO and where atmospheric turbulence distribution is 0.11 near ground with heights from 6.5m to 2.7m during night. Sky brightness in B and V band are 22.34 and 21.54. The extinction coefficient K,bv and K,v are 0.298 and 0.135. The seeing measurement is 0.72’,. In the recent years a new 2.4m telescope the second largest telescope in China, was installed there.

A night-sky luminance survey was carried on in Beijing to assess the level of light pollution. The luminance of the zenith night sky and skies in four directions at six sites with different distances from the city center was measured by using a photometric luminance meter. The Xinglong Station of National Astronomical Observatory was included to study the impacts of city lights on an astronomical observatory. The survey shows that the night-sky luminance decreases with increasing distance from the city center. Measurement results indicate that outdoor lighting in the Xinglong county town which is close to the observatory has non-negligible influence on the night sky at Xinglong Station.

Andalusia (Spain) houses several astronomical observatories, among them the main observational facility in continental Europe: Calar Alto Observatory. In recent years, the regional government of Andalusia has been setting up a regulation to protect the natural conditions of darkness at night all over the region. This regulation includes several outstanding features and poses specific rules to protect the influence area of Calar Alto Observatory.

The SAAO is at a geographically crucial site in the southern hemisphere between South America and Australasia. SAAO has a long history of involvement in infrared and optical astronomy that dates back almost two hundred years. The observatory expects to continue contributing to astronomical research for many years to come, using its small (0.5m, 0.75m, 1.0m and 1.9m) telescopes and their various instruments (ranging from spectroscopy to polarimetry and high-speed photometry), together with the Southern African Large Telescope (SALT) and other hosted international telescopes. In this paper, I discuss the capabilities and uses of the SAAO small telescopes, and the challenges that threaten astronomical research at the observatory, including light pollution and other emerging threats to the usually dust-free and dark-night-sky site at Sutherland. This is mitigated by the legislation called the Astronomy Geographic Advantage (AGA) Act of 2007 that protects the observatory from these threats.

Light Pollution is a global problem. Some local actions carried out by a network of professional and amateur astronomers in Argentina are changing the way to attack this problem, taking into account measurements, education, public activities, planetarium shows and legislation proposals.