Hey Ray! Light Pollution's Impact On The Sky

PITTSBURGH (KDKA) -- During the daytime, when you look to the sky you can't see stars, or sometimes planets that you can see at night.

While daylight is the obvious reason, at night we may not be able to see some of the good stuff because of different kind of light called light pollution.

You may have heard about air pollution or water pollution, but light can be a form of pollution, too. To learn more about light pollution, let's talk with our Friend, Mike Hennessy from the Buhl Planetarium at the Carnegie Science Center.

Elizabeth: Hey Mike!  What is light pollution?

Mike Hennessy: Light pollution is a lot of unneeded unnecessary light beyond what's actually being used and it's been scattered into the atmosphere, it can harm human health, it can harm wildlife. It can also just impact our ability to enjoy the night sky.

Ray:  If people weren't producing light at night, what would we see?

Mike Hennessy: Exactly so just 100 years ago everyone around the planet pretty much was able to enjoy a view of star stream sky littered with stars to be able to see into the band of the Milky Way galaxy. During the summer months. And now most folks around the world, I just don't have that opportunity to enjoy all the stars that nature can afford us.

Elizabeth: You could have seen the Milky Way from Pittsburgh?

Mike Hennessy: You really could have, and that's not to say that we can enjoy our city lights as well. But it is a matter of I think choosing the right technologies and the right applications, even the right colors and temperatures of our lighting to make sure that we can preserve the sky above us.

Ray: Light pollution is more problematic than just seeing stars, right?

Mike Hennessy: I think that's a good point. And it really is a big issue because light pollution is energy inefficient. So, it's estimated that at least 30% of all the lighting that we're casting outside is wasted like it's not being put to good use. That adds up to billions of dollars that we're spending to produce that energy, lots of carbon dioxide being pumped into our atmosphere that affects our climate so light pollution is a lot more serious than it might seem at first glance, but there were ways that folks can help at home. You can start with an organization called the International Dark Sky Association, and actually have a seal of approval that they put on different lighting fixtures that have the ideal color and temperature, and they were good at just directing that light downward.

Elizabeth: What can we do?

Mike Hennessy: I think if you want to waste folks and help our motion detectors dd                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             and timers.  That's a great way to make sure that you are using the lights and make sure things are safe at night, but you're doing it at just the right times.  Shielding on lights and directing light is very important. There are a lot of ways that we can help kind of take back our heritage of the night sky, but along with that I will also say that even in areas with high light pollution, there's still a lot to enjoy so get outside.

Mike told us about a certification that you can look for, to see if the lighting you are about to purchase is certified to reduce light pollution.  It is called "Dark Sky Lighting Certification".  You can learn more about that here.

Mike also told us about a "citizen scientist program" designed to track light pollution.  It is called Globe At Night.  More information can be found here.