Laser Policy

Astronomical League Laser Policy

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The following policy has been officially adopted by the Astronomical League, of which BAS is a member. This policy was originally published on page 24 of the June 2018 Reflector.

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Astronomical League Laser Safety Rules and Recommendations

The Astronomical League advocates the safe and responsible use of green laser pointers.

Laser Safety Rules

1. A laser pointer must only be used in accordance with laws of the state or municipality in which it is used.

2. Laser pointers should be transported with batteries removed.

3. Laser pointers used for astronomy should have an activation button which goes to off automatically when not being utilized.

4. Before activating a laser, users should check that no person, animal, motor vehicle, or aircraft is in the general vicinity of where the laser is pointed.

5. When not being used to point out objects, lasers should be safely stored in a pocket or container or have a protective cap placed over the aperture.

6. In the absence of adult supervision, lasers should always be safely stored away from children in a secure location.

Laser use guidelines and recommendations:

The most commonly used laser pointer currently used by astronomers is the neodymium diode laser which emits a green beam at a wavelength of 532 nanometers. Note that in terms of eye injury hazards, the color does not matter. More milliwatts mean a greater potential eye hazard, no matter what the beam color. (This is for visible lasers; for infrared or ultraviolet lasers, the primary injury area is the cornea and not the retina.) For star pointing, green is best. The human eye sees green much better than the same amount of red or blue, so a 5-milliwatt green laser appears to be 5 to 10 times brighter than a 5-milliwatt red laser. Looking at a green beam in the sky should not adversely affect night vision. To keep your night vision, avoid looking directly at the laser dot on a nearby or light-colored surface.

1) Laser pointers can be valuable tools for outreach with those new to the hobby. For solo or small group use for pointing out objects in the sky, a 5-milliwatt green laser is completely adequate. It is considered a class IIIa laser and is recommended for stargazing purposes. For a larger group, or where the air is especially clean and dry, slightly higher power, such as 10 to 25 milliwatts, will be better. The absolute limit for this application should be about 50 milliwatts. There is no reason to use more than 50 milliwatts for astronomical pointing applications.

Higher-class lasers are usually unnecessary and carry more potent warnings from the U.S. Food and Drug Administration (FDA). The League does not encourage use of higher-wattage, higher-class lasers for stargazing. In some places, handheld laser pointers with an output greater than 1 milliwatt (classes IIIb and IV) are considered prohibited weapons. According to the FDA, promotion of lasers above 5 milliwatts “for pointing and amusement” violates FDA requirements and U.S. law. A caveat: many lasers have been found to be mislabeled or misrated, causing confusion and misjudgment.

2) Never point a laser at an aircraft, no matter how distant. Laser pointers, although low power, are highly collimated, maintain focus and can be harmful if not illegal for such use.

U.S. law signed by President Obama in February 2012 makes it illegal to knowingly aim a laser pointer beam at an aircraft or at the flight path of an aircraft. A slow-moving, distant aircraft can look like a star. If you are doing astronomy pointing at a “star talk,” use the laser pointer to circle unknown or faint objects. Don’t point directly at an object unless you are sure it is a star (like the familiar bright stars in Orion’s belt or the Big Dipper).

3) Use sparingly—only long enough to point out an object. Once the object is identified, turn the laser off.

4) Star parties often have rules for laser use. Attendees should check the policy at each event, and event organizers should have a policy as to where and when lasers may or may not be used.

5) Since astrophotography is an ever more popular activity with which lasers interfere, constant-on lasers used for telescope pointing are not recommended for use at events such as star parties. Such use should be reserved for solo observing.

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Below is printable PDF version of this policy as it appears on page 24 of the June 2018 Reflector.