Monthly Archives: March 2014

All-Sky Night-Sky, Earth Hour

Earth Hour Comparison - Night Sky 28th and 29th March 2014. Images are un-processed with respect to saturation and other effects, and are of same exposure details.

Earth Hour Comparison – Night Sky 28th and 29th March 2014. Images are un-processed with respect to saturation and other effects, and are of same exposure details.

Does “Earth Hour” make a difference from a night sky darkness point of view? I have always been skeptical, and do remain somewhat skeptical, but it was interesting to experience two consecutive nights this weekend of which one included “Earth Hour” (29th March 2014). Both images were taken from the same location (give or take 10 metres) 200km south-east of Perth, Western Australia.

The left image shows the all-sky view from 28th March, and the one on he right from the 29th March. The 28th March had some cloud cover, as evident around the periphery of the image. The 29th March was a 2 hour clearing between cloud banks. The cloud on the 28th March likely emphasised the light pollution situation, while the recent rain and weather system may have contributed to the increased green Air Glow on the 29th. From this location is is normal to see significant light pollution from Perth and in recent years from other nearby towns such as Narrogin. A such while the light pollution may be emphasised somewhat by the cloud on the 28th, I am amazed to see such a lack of light pollution in the image from the 29th.

One contributing factor, in addition to Earth Hour, maybe localised cloud on the 29th. It is possible that at the time of the photograph localised cloud was covering and enclosing light pollution from Perth and nearby towns, hence “trapping” the light pollution and limiting it’s visibility from my location. It’s not possible for me to know how much this influenced the situation, but either way the difference in light pollution, the almost absolute lack of it on the 29th, is quite a stark contrast and blatantly obvious.

Perth Observatory Star Viewing Night

Celestron 14 inch Telescope at Perth Observatory Star Viewing Night

Celestron 14 inch Telescope at Perth Observatory Star Viewing Night

Being a volunteer Star Viewing Night (SVN) host at Perth Observatory is great fun and rewarding. The public love coming along to see the night sky, and kids become enthused about science and astronomy.

I’ve always wanted to get some nice astro photographs of the Perth Observatory Star Viewing Nights, partly as a historic record and partly for use by the Perth Observatory as promotional material. As a host I usually don’t have time to take photographs, and so such a task required a dedicated trip to the Perth Observatory, on Saturday the 1st March 2014.

Below are some photographs of the Star Viewing Night activities at the Perth Observatory.

All photographs are available for purchase as prints or digital files for copyright use and personal printing.