Protecting our dark skies: July 2026 meeting recap

By Dirk Goës

The July 2026 meeting was held in person and on Zoom at Sydney Observatory.  47 people attended the meeting including 27 members and 20 visitors.  26 people attended in person and 21 via Zoom.  SCS President Dr Toner Stevenson welcomed all existing and new members and acknowledged First Nations peoples.  SCS Secretary, Elizabeth Cocking, updated members on matters to do with the society.  Committee member Dr Andrew Wood gave a short presentation on his latest variable star observations.  You can read more about Andrew’s observations in his blog post. 

Our keynote speaker for July was Marnie Ogg, the founder of the Australasian Dark Sky Alliance and a leading advocate for the protection of dark night skies in Australia.  Marnie explained that light pollution is the fastest growing form of pollution in the world, but also the easiest to solve! 

It is as easy as switching off unnecessary lights at night.  Where lights are necessary, they should be directed to only light up the desired area and not spill over into the environment.  They should also be warm coloured lights, ideally with a colour correlated temperature (CCT) of 3000 K or less. 

Figure 1: A simple guide to dark sky compatible outdoor lighting.

Our view of the night sky is literally disappearing before our eyes. A 2023 study published in the journal Science found that light pollution is increasing by up to 10% per year.  Not only does light pollution rob us of a starry sky, but it also affects our health by disturbing our circadian rhythm. It also impacts the circadian rhythm of wildlife, for example nocturnal creatures that rely on dark nights to hunt and forage. 

For example, Marnie pointed out that if you light up a tree at night you are evicting all the wildlife and the insects from that tree.  Not only are you robbing those creatures of a home, but you are also impacting the health of the tree by removing beneficial insects. 

Modern energy efficient LED light bulbs have exasperated the problem by producing more glare as they produce more blue short wavelength light.  They also produce UV light which human eyes cannot see but many animal species can, further upsetting their circadian rhythm. 

Figure 2: Many animals and insects see short wavelength UV light which humans do not (Credit: Marnie Ogg’s presentation). 

Through advocacy by organisations like the Australasian Dark Sky Alliance and Dark Sky International reducing and preventing light pollution is slowly getting onto political agendas.  For example, just this year the Sunshine Coast Council cooperated with the Australasian Dark Sky Alliance to designate the Sunshine Coast hinterland Australia’s second International Dark Sky Reserve. 

Palm Beach Headland in Sydney is Australia’s first Urban Night Sky Place and Warrumbungle National Park right next to Siding Springs Observatory was Australia’s first Dark Sky Park. 

Perhaps the most impressive example of what can be achieved comes from France where new federal laws around light pollution, introduced in 2019 have dramatically darked French skies as shown in the figure below. 

Figure 3: The dark areas show the dramatic decrease in light pollution across France from 2019 to 2024 (Credit: Marnie Ogg’s presentation). 

New threats are also on the horizon with the continued exponential growth of satellites in our skies and proposals such as start up company Reflect Orbital who want to place mirrors in space to reflect sunlight onto Earth at night.