This is a map of light pollution in the area around Austin, Texas.

Those purple markers (which are clickable at the map’s website) indicate how much or how little night sky is visible. For the ones near the city core, the emphasis is on “little.” In 2007, the city passed regulations aimed at reducing the amount of light that brightens the night sky, but old fixtures — and the city’s highways — were grandfathered in until 2015.

Via rutlo
Photo by rutlo on Flickr.

Yesterday, they took more direct action. The city council approved spending up to $15 million to replace or upgrade half of Austin’s streetlights. The decision will result in the removal of existing plastic domes from under the lamps, which tend to diffuse the light broadly (and inefficiently). More importantly, it will also buy 35,000 LED lights, which use half the power of the existing bulbs and which last up to 15 years.