Sports lighting impact at W.A.S. Froemming Park observatory

In the summer of 2002, the Milwaukee Rampage installed sports lighting for their soccer field. This is unfortunate for us because they are right in our backyard.

UPDATE: The Milwaukee County Sports Complex has a new user-- The Ironman Football League. They started using the field in 2005 and the main problem with this user is that they are using the field right at our prime times--August through October (when most of the showpiece objects are up in the night sky) and they operate on Friday and Saturday (our prime days) with the latest game starting at 8:00pm.

Note that all pictures on this page are taken as to be representative of what your eye would see. No photo manipulation was used.

Below are comparision images taken from the same vantage point. The one on the left was taken at twilight and the one on the right was taken at night with the lights on. Notice the amount of glare from the lights facing us and the dome of light that is above the lights.

Here is an image of the lights just turning on. This picture was taken from our observatory field in Froemming Park through one of our telescopes. Notice that you can see every bulb in every light. These lights are not cutoff to just light the soccer field. If you can see the bulb, you are going to get direct glare from the light as demonstrated above. If you are not at the location where the lights are intended to light, i.e. the soccer field, then this is wasted light as it is not lighting what it is intended to light.

These lights even show a glare from the back side of the lights as show below (look for the purple glow, especially in the two middle rows of lights). We believe that this is light reflecting off of the back of the reflectors from the light of a bulb of an adjacent light.

So what happens when lights are not cut off to light up what they are intended to light. You get light spilling everywhere, even where it is not wanted. This is called light trespass. You can see an example of light trespass in the picture below. Note the shadows that are cast from these lights and notice that it is still twilight.

This picture shows the extent of the light trespass.

Below is a similar image with just the west bank of lights turned on. This picture shows that the trees are directly lighted by just this one pole of lights. It illuminates these trees that are about 500 feet away to the equivalent of broad daylight.

Wehr Astronomical Society
www.wehrastro.org