Astronomy Interests to Push Satellite Light Pollution Regulatory Fixes at UN

The satellite working group also recommended encouraging nations to support international standards on space data sharing and maximum brightness of objects in space, said co-chairman Andrew Williams, European Southern Observatory institutional relations officer. He said funding is needed for astronomy interests' investments in mitigating the growing problem of light reflected off mega-constellations corrupting astronomical observation data. There also could be funding for industry innovation such as lower-reflectivity surfaces for satellites, he said. National space policy boards and committees should include astronomy representation, "something generally not the case right now," he said.

Satellite operators are slowly becoming aware of the need for early consultation with astronomers, when constellations are being conceived, to try to avoid reflectivity issues, Williams said. He said such consultations are also something governments could conceivably compel. He said a template for those interactions is needed.

IAU representative on COPUOS Piero Benvenuti, co-chairman of the recommendations summary, said the message to COPUOS should be that the astronomical community has had some success in mitigating reflected light from mega-constellations, but it also seeks some regulatory limits. Those should include limiting reflected sunlight to a particular magnitude, and making up-to-date data on satellite locations and orientations readily available. Ultimately, national regulators should make license applications include light reflection prevention analyses, and too little effort on mitigation on the part of operators should mean no license, he said. Benvenuti said discussion is needed about satellite operators paying for the mitigation efforts, such as algorithm development, that the astronomy community has been undertaking: "Why should astronomy bear the cost?"

With the proliferation of mega-constellations eroding scientific access to both radio spectrum and the night sky, radio astronomy and optical-infrared astronomy interests are in alignment, said University of Virginia radio astronomer Harvey Liszt, chairman of the radio astronomy working group. He said the working group recommends NGSOs be required to avoid direct illumination of radio telescopes and radio quiet zones, particularly when for high-power satellite applications capable of burning out radio astronomy receivers. He said NGSOs also should be required to have sidelobe levels low enough that their indirect illuminations don't cause radio telescope or radio quiet zone interference.

A direct illumination requirement would involve satellite operators switching off or redirecting beams, which could be difficult to achieve, though it merits discussion, Benvenuti said. He said the sidelobe power limits could be challenging due to the sheer number of satellites expected to be in orbit. He said there should be a discussion with the ITU about how much it can intervene in radio astronomy issues and what needs to be addressed by COPUOS.

Benvenuti said the astronomy community might start contacting national delegations that expressed interest in light interference to see if they can submit a working paper, which would have more political impact than just the Dark and Quiet Skies conference report.

Some discussion involved using satellite-caused light pollution to bring to COPUOS the wider issue of artificial light pollution and possible regulatory means of addressing it. "The inhabited world is slowly blinding itself to the night sky," said Richard Green, director-University of Arizona's Large Binocular Telescope Observatory. Niklas Hedman, U.N. Office for Outer Space Affairs chief of committee, policy and legal affairs section, said COPUOS is more likely to respond to the narrower issue of satellites' effect on ground-based astronomy.