April 20-26 is 2014 Dark Sky Week. It's to highlight - er, make that lowlight the need for responsible night lighting. It's not just for astronomy, but inappropriate lighting is a danger to wildlife, to human health, and can cause accidents and encourage crime.

See what Light Pollution does to us and some ways of combating it.

Hello Mona,

Thanks for a very interesting article if a bit disturbing. As usual, 'hupersonity' is smart enough to know better but I doubt that much will be done - our world is too self-indulgent and grasping.

I often go to the planetarium here in Johannesburg where they have shows about what is happening in the skies above us right now and so on ... and my favourite part of the evening, repeated by request, is when you are asked to settle back into your seats and look at the sky.

They point out all sorts of things and you smile and appreciate them of course. Then you are asked to close your eyes for 3 minutes and listen to the music and at the end of the 'tune,' look and see what you see.

They then say that what you have seen is the night sky over Johannesburg and, when you look up again, it is the same sky as seen from the Karoo, only this time they are able to point out other phenomena too that can't be seen readily because of that light pollution over the city.

The beauty, the majesty, the mystery ... makes me cry with joy. While I feel so small and absolutely insignificant, I also feel privileged to be part of this great universe. Amazing.

Thanks for everything astronomical,

Cheers

Here is a picture of the Milky Way seen in dark skies. Fewer and fewer people in the world are able to see this beautiful sight. Dark sky surveys show, for example, that over half of the people of Britain can't see this from home.

Can you see the Milky Way from where you live?

Lestie, the planetarium sounds great. I love going to a planetarium. Last year on the Queen Mary 2 - which has its own planetarium - my colleague gave some planetarium shows. It was to let people compare the stars we could see from southern Africa to those in Europe. And of course, what we could see from the ship when it was clear. I was very excited to see the Southern Cross. Or the Southern Triangle, as I called it, when it always clear enough to see all four stars.

Light Pollution – Facts for Kids
Thieves are stealing something that belongs to you. Something you've inherited from countless generations of your ancestors: a view of the night sky. Unnecessary lighting has hidden it from you. The same lighting damages wildlife, increases air pollution and can damage your health. What can we do?

The Dark-Sky Association explains why poor lighting causes problems and ways of solving them.

Nobody wants to be robbed, but light doesn't keep us safe.

People are more likely to get burgled, or robbed in the street during the day or summer months when it's already light. Criminals need light too! Worse than that, some "security" lighting is so bright, it hides a would-be intruder.

Studies of how lighting affects the crime rate haven't shown that night lighting cuts crime. A few studies suggested that it increased the crime rate, some were neutral. The most interesting ones showed that installing the lighting decreased crime in the area . . . but that this decrease showed up during the daytime too! So probably the light itself wasn't the essential factor.

Hello Mona and all,

How serendipitous! Right now we are beefing up the security aspects of our building by installing cameras and electric fencing and gates etc. Part of the important discussion was what to do about making the spotlights work for us and the cameras and not for intruders or baddies.

After al the work is finished, it will certainly be very difficult to get into our building unless you belong here ... but as usual, we have to rely on our residents not to just let anybody in. Police reports often cite the fact that mischief was probably caused by inside information and action.

Ah well, we feel safe.

Cheers

Nocturnal birds or those that migrate at night are confused by bright lights. They can fly into buildings or other structures. Or just circle until they are exhausted. This image of all the birds caught in these lights is very sad.

Hi Mona,

Sorry but I am too much of an ostrich and couldn't bear to follow your link or look at the picture. I hate what we do and wish so I was not part of it, but I am as hateful as I feel. A big piece of my heart remains sad for what we are doing to the earth in myriads of uncaring and self-indulgent ways.

Sad Sack indeed.

Cheers

Hong Kong is the most light-polluted city on Earth. But what might it look like at night if Hong Kong had a dark sky? Isn't this picture amazing! The photographer Thierry Cohen shot the cityscape "day for night" and then added a night sky. Not just any nice sky he could find, but one that he shot at the same latitude as Hong Kong, so that it really could look like that if it were dark.

He also has pictures from New York, San Francisco, Rio de Janeiro, Singapore and other cities.

You can see here a set of Thierry Cohen's nightscapes. I hope you enjoy them.