Sunday, September 7, 2014

Stargazing in Tucson

Shopping mall parking lot - LPS lighting with halide lighting in adjacent property 

Stargazing is a remarkable activity and even if you don't know what to look for, an overhead canopy filled with stars is awe-inspiring. The Dark Sky Society (and astronomers everywhere) agree. Me too!

Nowhere does this have more power than Tucson, Arizona where I've been this past week. The city has some of the strictest regulations to keep light pollution down. Like other communities with national astronomy observatories, it promotes those dim, orangish-hue low pressure sodium lights (LPS) for streets and parking lots.

I visited mall parking lots this week in and around Tucson. LPS are everywhere. They are awful!

Shopping plaza parking lot with pedestrians walking across - look carefully
The engineering lighting standard for mall parking lots is 3 footcandles (FC). An on-line survey of 9 communities reports an average 1 FC in most of those communities.

In one lot that I visited I doubt LPS produced 3 FC or even 1 FC! I love stargazing but I would not enjoy walking those lots at night.

Thankfully the economy is changing the story. Tucson is in the midst of the nation-wide LED transformation for more savings and it is switching LPS street lights over to Light Emitting Diode lighting. I hope mall owners in and around Tucson get the message. I would not want to be a victim walking to my car. Nor would I want to be a property owner sued by a victim of violent crime in those spooky, target-rich lots.

Tree tops benefitting from LPS lighting