Light pollution is excessive or obtrusive artificial light. It is a broad term that refers to multiple problems, all of which are caused by inefficient, unappealing, or (arguably) unnecessary use of artificial light. Specific categories of light pollution include light trespass, over-illumination, glare, light clutter, and skyglow.
Otero County is home to the National Solar Observatory (NSO), Apache Point Observatory (APO), Sloan Digital Sky Survey (SDSS), Tzec Maun Observatory and the New Mexico Skies astronomy enclave. In addition to these major observatories, Otero County is home to countless private observatories. Our dark skies are a natural resource, the White Sands Star Party draws visitors from around the country. While an economic impact assesment has not ben conducted, astronomy pumps millions of dollars into our community each year.
Light pollution obscures the stars in the night sky for city dwellers, interferes with astronomical observatories, and, like any other form of pollution, disrupts ecosystems and has adverse
health effects. Light that shines upward doesn't help reduce crime or do anything constructive, it just makes it harder to see the stars. But most importantly, light pollution wastes energy and increases energy bills.
Regional Light Pollution Map
Light trespass occurs when unwanted light enters one's property, for instance, by shining over a neighbor's fence. Light trespass can be reduced by selecting light fixtures which limit the amount of light emitted in all directions and redirect it only needing it.
Over-illumination is the excessive use of light. Structures lit up at night using upward-facing lights are primary culprits. Over-illumination contributes to skyglow, an effect that can be seen over populated areas. It is the combination of all light reflected from what it has illuminated escaping up into the sky and from all of the badly directed light in that area that also escapes into the sky, being scattered (redirected) by the atmosphere back toward the ground.
Light pollution can be controlled through simple means by:
International Dark Sky Association
Starry Night Lights
(a) The purpose of this chapter is to restrict the emission of undesirable light rays into the night sky which are detrimental to aviation and to astronomical observations. The provisions of this chapter shall apply to all outdoor lighting devices used for illumination or advertisement.(b) The provisions of this chapter do not apply to incandescent lamps of one hundred fifty (150) watts or less; glass tubes filled with neon, argon or krypton; outdoor advertising signs constructed of translucent material and wholly illuminated from within and fossil fuel light sources.
The provisions of this chapter are intended to supplement other applicable codes and requirements. Compliance with all applicable provisions of building, electrical and other codes must be observed. In the event of a conflict between the requirements of this code and other requirements, the more stringent requirement shall apply.
(a) General requirements. Except as otherwise provided below, all lighting devices or fixtures shall be shielded in such a manner that light rays emitted by the device or fixture, whether directly from the lamp or indirectly from the fixture, are projected below a horizontal plane running through the lowest point on the fixture where light is emitted.(b) Low-pressure sodium. Low-pressure sodium lamps shall be shielded in such a manner that the lowermost edge of the shield is below the plane of the centerline of the light source or lamp so that light emission above the horizontal plane is minimized.
(a) Only shielded outdoor light fixtures may be installed for security purposes or for illumination of commercial establishments.(b) Shielded, low-pressure sodium outdoor light fixtures or high pressure sodium lighting equipped with a minimum ninety degree side cut off internal louver may be installed to provide illumination for public streets or for any purpose other than that specifically listed in subsection 31-01-040(a). However, in the case of the replacement of light fixtures installed to provide illumination for public streets, low-pressure sodium outdoor light fixtures or high pressure sodium lighting equipped with a minimum 45-degree side cut off internal louver shall only be required if existing circuitry will allow the replacement of an individual light fixture with a low-pressure sodium light fixture or high pressure sodium lighting equipped with a minimum 45-degree side cut off internal louver.(c) All outdoor light fixtures maintained on public or private property, whether installed before or after the effective date of this chapter, shall be turned off between 11:00 p.m. and sunrise except when used for:(1) Commercial and industrial uses (such as sales, assembly and repair areas) where business is conducted after 11:00 p.m. but only for so long as such use continues;(2) Illuminated advertising signs on the premises of a business while it is open to the public;(3) Lighting necessary for security purposes or to illuminate walkways, roadways, equipment yards and parking lots; or(4) Recreational use that continues after 11:00 p.m. but only for so long as such use continues.(d) The operation of searchlights for advertising or commercial purposes is prohibited.
(a) Flashing lights. The use of flashing, rotating or pulsating lights in/on any outdoors sign or other lighting device is prohibited after one (1) year from the effective date of this chapter. This provision shall not apply to flashing, rotating or pulsating lights intended to warn of hazards and danger.(b) Residential spill-over. Offstreet lighting shall be shielded and/or directed in such manner that it only illuminates the user's premises and does not spill over into neighboring residential areas so as to interfere with the peaceful enjoyment of residential properties.
Except as provided in section 31-01-050, all outdoor recreational facilities designed for specific sporting events are exempt from the shielding requirements of this chapter. All nonconforming fixtures must be abandoned or replaced by fixtures conforming to this chapter not later than July 1, 2005.
Even though Alamogordo has a lighting ordinance, several communities in the southwest have adopted stricter regulations. Advances in illuminated sign technology, such as LED billboards are not addressed
in the Alamogordo ordinance.
Simple Guidelines for Lighting Regulations for Small Communities, Urban Neighborhoods, and Subdivisions Model Lighting Ordinance (with users guide)
Additional Resources for Controlling Light Pollution
Simple Guidelines for Lighting Regulations for Small Communities, Urban Neighborhoods, and Subdivisions
Model Lighting Ordinance (with users guide)