Driving home one night from an interview at MSU, I got a shock. My wife and I pulled off I-55 at Mount Zion Road to change my baby's diaper. There, for the first time in years, we saw the Milky Way. I'd been trying for months to see stars in Baton Rouge and simply gave up under the impression that the town I lived in was under some kind of perpetual haze. The interstate had looked foggy before we pulled off, what could account for the difference?
Returning from another interview at Ole Miss, I decided to open up the sun roof and find out where the stars shone the brightest. Once again, it turned out that the Mount Zion Road exit was best. We noticed that the closer we got to towns, the dimmer the stars became. Louisiana was hopeless.
What we had observed was light pollution. My page here tries to reproduce the work found in this one. The satellite images don't line up easily with maps, but the following composite is close to what we had seen. The table was taken directly from the starcruiser site.
| Zone | Color | Description |
|
1
|
Black | Trace artificial LP |
|
2
|
Blue | Artificial LP is 10% over natural sky brightness (?light polluted sky?). Long exposure astrophotos might show some light pollution gradient, but visual observing is relatively unimpaired. |
|
3
|
Green | Artificial LP is 50% over natural sky brightness. Modest impact on deep sky observing and imaging. Milky Way shows structure |
|
4
|
Yellow | Artificial LP is equal to natural sky brightness (total sky brightness is doubled). Serious impact to deep sky observing and imaging. Milky Way visible but not crisp. |
|
5
|
Orange | Milky Way not visible |
|
6
|
Red | Less than 100 stars visible over 30 degrees elevation |
|
7
|
White | Hopeless? |
There are virtually no places in South Louisiana to look up at the night sky. Indeed, the white regions are hopeless. Only the sun, moon and three or four very bright planets and stars can be seen in Baton Rouge and New Orleans. Favorable conditions exist at the south end of Chandelfleur Island, if you have a boat, but even large areas of the sea are blotted out by offshore rigs. Even Lake Pontchetrain, with the world's longest bridge, is so polluted you might not see the Milky Way. You can find some lower light polluted areas in some state parks and there is camping on Grand Island. The closest places land and sea meet with no light pollution are the Saint Joseph Peninsula and Saint George State Parks on the Florida pan-handle.
Prospects are not much brighter in North Louisiana, though the sky is not hopeless. There is one black spot, which looks orange on the composite map, around the Chalk Hills and Enterprise, LA. There are several National Forests with lower light pollution, Kissache and Homochitto.