Good morning on this so-so Friday.

The peak of the Perseid meteor shower is this weekend, and tonight and Saturday night are the best times to watch.

Observers can expect to see at least 80 meteors an hour streak across the sky.

But not in New York City. And you can thank light pollution for that.

To better understand light pollution, or excessive artificial light sent into the night sky, we turned to John Barentine, an astronomer and the program manager at the International Dark-Sky Association, an organization working to reduce light-polluted skies.

What are the negative effects of light pollution?

Light pollution is most harmful to wildlife and ecology, Mr. Barentine said, because it can interrupt the circadian rhythms of different species and interfere with their ability to mate or feed. For example, baby sea turtles use light reflecting off the ocean to guide them to the water. Artificial light can cause them to move away from the water, or in circles, until they exhaust themselves or are picked off by a predator. Not only is the energy used in creating light pollution wasteful, it adds to climate change and is a drain on our energy resources, he said.