However a significant proportion of this outdoor illumination escapes upward into the sky creating sky glow that washes out the stars. It also escapes sideways creating unwanted light trespass and glare in the urban environment. This wasted light is due to a large proportion of outdoor light fixtures that lack the proper aiming and shielding properties. In some location lights also burn all night serving little if any purpose when they may be dimmed or turned off. This wasted light is known as light pollution. It wastes money and energy often creating a nuisance. It casts a pall of light in the sky over a town or city at night seen from the country and a perpetual twilight sky that is never truly dark from within the urban environment.

Light pollution halos surrounding cities grow as population grows and urban development spreads. We now are forced to travel ever further to escape the urban sky glow to experience a natural starry sky resplendent with the Milky Way galaxy stretching across the sky. Amateur and especially professional astronomical observatories are now increasingly compromised in their effectiveness to record the faint light of astronomical objects due to encroaching sky glow from growing nearby cities. It is becoming more difficult to escape the bright urban sky glow to experience the natural, true night of a star studded sky and its calming and wondrous vistas.

Recent scientific research is now uncovering some of the deleterious effects of light pollution on the environment and human health. Millions of years of evolution living creatures have adapted and synchronised to the circadian rhythm of the day-night cycle. Light pollution interferes with this adaptation. In animals it leads to disrupted feeding, reproduction cycles, and migration behaviour. In humans it is known to disrupt melatonin production at night leading to ailments such as obesity, diabetes, cancers and perpetual tiredness to lack of proper rest in darkness.

We humans have recognised the healing and relaxing effect of urban parks and nature reserves to recuperate and reconnect with the healing effects of the natural environment. We have gone to great efforts to preserve such natural areas and to prevent them from the threats of pollution and intrusive development for the cultural, educational and relaxing benefit these reserves afford. This same recognition should now be extended to protection of the night sky.

Australia is less light polluted overall due to lower population and wide apart cities.  However most of the population is living in densely populated urban areas with bright sky glow. The River Murray Dark Sky Reserve is just outside the light pollution halo of Adelaide. Map: Light Pollution in the World

We must recognise our night time starry environment affords the same benefits that is also under threat from light pollution from encroaching urban development and needs protection. The starry sky at night is said to have inspired the first of the sciences, astronomy. It taught us our place in the universe, encouraged invention, exploration and aided navigation. Astronomy still probes the depths of the universe and needs protected dark skies around observatories and dedicated public parks to encourage discovery and appreciation of the night sky.

This is why we propose to create a dark sky reserve in the Mid Murray area. This region has some of the darkest night skies near a major population centre (Adelaide) than any where else in the world. It is a perfect opportunity to put in place protection of the night sky for the benefit of all who visit who wish to reconnect the the story of astronomy passed down from the earliest star gazers through the indigenous peoples of the land to story told by modern astronomy.

Martin Lewicki

Sky Quality Meter (SQM) Readings Across the River Murray Dark Sky Reserve

In order to acquire IDA accreditation  we need to provide sky brightness measurements across the designated area. During 2017 and currently on-going SQM meter (image at right) readings show the sky brightness  is 21.9 magnitudes per square arc second. This is about the darkest sky possible with 20.0 the darkest practical. A typical urban sky in Adelaide is about 19. This makes RMDSR about 15 times darker than the urban sky! (Note the SQM reading are logarithmic with higher reading indicating darker sky while lower reading  indicating a brighter sky ) More on the SQM here.

                              Below: An example coverage of SQM readings as of May 2017 in the RMDSR area.

Three Comparative  images of the Carina region of the Milky Way

Three photographs taken of the Eta Carina region of the Milky Way illustrate the effect of different levels of skyglow on the appearance of the night sky. As a rule the sky is darker and more starry further from light polluted urban areas. Eta Carina is a one of the brightest parts of the Milky Way. Its pink glow that shows in photographs comes from fluorescence caused by the ultraviolet radiation of hot stars ionizing surrounding clouds of hydrogen gas. Distance ~7,500 light years.

Images  with Pentax K-x DSLR. 24mm,  f4, iso1600, 6Mp, reduce to 800x531.  Approximately the same region of sky images from three locations with from very dark sky at a RMDS site to urban light polluted sky. Images: Martin lewickl

What is an SQM?

What do the SQM numbers mean?

Read the full documents downloads (PDFs)

                                                  All images and illustrations by Martin Lewicki unless stated otherwise.