CPS Newsletter #1

The Centre for the Protection of Dark and Quiet Sky from Satellite Constellation Interference (CPS in short) was created in 2022 by the International Astronomical Union to coordinate efforts and unify voices on mitigating the impact of the large satellite constellations on astronomy and the pristine appearance of the night sky. Its mission is carried out by its two host institutions (NOIRLab, in Tucson, USA and SKAO, in Manchester, UK), which coordinate the voluntary contribution of more than 400 affiliated members worldwide.

In the three years since its inception, the CPS has achieved relevant goals in all four areas, or “hubs,” of its activity. These include the scientific characterisation of satellite interference, the development and testing of possible mitigating measures in collaboration with satellite companies, the analysis of the existing relevant policies, and the engagement of society at large in understanding the epochal change in the use of outer space.

This coordinated effort resulted in the development of a series of recommendations addressed to stakeholders (astronomers, satellite companies, the space industry, and policymakers), which now require gradual implementation to become effective. The task is very demanding and will require acquiring additional resources through targeted fundraising actions and a more effective utilisation of the generous potential contribution of the large community of affiliated members. The key to both actions is a better and up-to-date flow of information about the Hubs' activities, particularly about specific projects that can benefit from the expertise and availability of our members.

This is the main purpose of this quarterly CPS newsletter, which is primarily intended for the affiliated members, albeit hopefully of interest to a larger audience. For this reason, its style will be kept as concise as possible, with links to more detailed documents. Each Hub will, in time, describe well-defined projects suitable to be carried out autonomously by affiliated members. A typical example, based on the wide geographic distribution of our members, could be the translation into different significant languages of documents intended for the public at large.

We are looking forward to effectively working together to defend our sky!

Piero, Connie, and Federico, CPS Management Team

SatHub continues to coordinate several observing campaigns to monitor satellite brightness, and welcomes contributions from members and the broader community through our new Satellite Constellation Observation Repository (SCORE). A paper introducing SCORE is forthcoming. SCORE is designed to be publicly accessible for all observers in the optical/IR, including visual observations, research-grade telescope measurements, and anything in between. Please use this opportunity and upload any available observations of artificial satellites to SCORE! We welcome user feedback on the CPS Slack in #sathub_software.

Spotlight: Five+ years of Starlink, a retrospective
The SatHub leads are writing a new review paper summarizing the many generations of Starlink satellites and how their brightness has evolved over time and across the EM spectrum. If you have Starlink observations that are not yet published, uploaded to SCORE, or available on the arXiv, please reach out on the CPS Slack in #sathub_optical_observing or #sathub_radio_observing.

Have you tried SatChecker yet? It’s the IAU CPS SatHub service for answering, “When will this satellite be visible from my location?” Learn more here, which includes example Jupyter notebooks for queries and plots.

SatChecker also has a beta field-of-view (FOV) service, available here, which aims to answer, “What satellites are overhead tonight?” We welcome you to try it out and share feedback on the CPS Slack in #sathub_software. Please note SatChecker FOV is in active development, so the interface is subject to change and it may experience unannounced downtime.

SatHub continues to hold monthly member meetings over Zoom, typically on the first Wednesday of the month, where the agenda is set by you. The schedule alternates between more Pacific vs. Atlantic friendly times. Mark your calendars for Mar 5 at 1500 UT, and likely continuing the pattern in subsequent months. Final meeting details will be shared on the CPS Slack in #sathub.

Many SatHub members joined The Committee for the Protection of Astronomy and the Space Environment (COMPASSE) meeting at the recent 245th American Astronomical Society meeting near Washington, DC in January. There were opportunities to try a 3D headset visualization of a night sky swarming with tens of thousands of bright satellites, visit Capitol Hill to meet with congressional staff, attend a special session featuring a panel of regulators from US Federal agencies, and more. You can check out the AAS 245 iPoster gallery.

Please invite your colleagues to join us — SatHub needs all the help we can get to protect our skies! We ask prospective new members to complete the form at cps.iau.org and select SatHub.

Siegfried, Mike, and Meredith, SatHub co-leads

• We are excited to announce the publication of our latest report, which examines the international and national governance of orbital light pollution and spectrum interferences. This critical issue takes center stage in space governance discussions, particularly as the UNCOPUOS Scientific and Technical Subcommittee addresses it under the new Agenda Item 15: Dark and quiet skies, astronomy, and large constellations: addressing emerging issues and challenges. The report builds on research conducted throughout 2023 and forms part of the Policy Hub's ongoing work. We will continue refining and updating our analyses, ensuring they incorporate the latest developments in national, regional, and international policy and legal frameworks. You can access the reports here and here.
• The Future Space Technologies Working Group is finishing up their initial reviews and assessments. We anticipate that their preliminary results will be available in the first half of 2025.
• Additionally, we are actively defining our goals and projects for the next three years and will soon resume operations with our members.
• Feedback, questions, or contributions to the reports and our activities are welcome, feel free to reach out to the Policy Hub co-leads at policy@cps.iau.org!
  
  Aaron & Giuliana, Policy Hub co-leads

The Industry & Technology (I&T) Hub is playing a crucial role in bringing together the satellite industry, increasing the awareness about dark and quiet skies and facilitating the interaction with other hubs of the CPS. Currently, the Technical Advisory Group (TAG) includes representatives from 16 of the leading satellite constellation projects and manufacturers. Recruitment plans are underway for 2025 to expand this group further by engaging additional manufacturers, new satellite operators, and innovative technology providers. This expansion will deepen industry involvement and promote collaborative solutions to challenges faced by the astro community.

A central element of the Hub’s value to companies is the Astronomer Guides Programme, which plays a critical role in pairing an astronomer with a company on a one-to-one basis. These guides will provide clear insights on the challenges for astronomy, and will build a relationship with the satellite company to foster the implementation of existing mitigations or developing new ones.

The I&T has collaborated with the SatHub to coordinate on-orbit observations and periodically taps into the support of some of our individual CPS volunteers. Their commitment and expertise have helped sustain momentum and drive key projects forward. In addition to these efforts, the I&T Hub plans to capture a summary of industry engagement and contributions to date, including mitigation approaches and strategies, gaps in resources and other challenges.

Collectively, these initiatives highlight the I&T Hub’s proactive approach in engaging leading satellite industry players under the CPS enhances the dialogue with the astronomy community. We are looking forward to 2025, to an even broader representation of industry players in the I&T Hub to enrich the collaboration on dark and quiet skies!

Tim and Chris, I&T Hub co-leads

Since its inception, it has become clearer that the mission of the CPS Community Engagement Hub is as much one of education as it is of engagement. To that end, CE Hub has taken actions to inform stakeholders and the public about the issues that CPS faces, such as by producing its "SatCons 101" learning curriculum.

In 2024, it held the first CE Hub town hall meeting, and it plans three similar events in 2025. These events are an opportunity for participants to learn more about the issues and hear answers to their questions from experts. We will inform CPS members of these upcoming events via email once specific event details are determined.

The Hub has also recently developed a strategic communications plan that will guide its work in coming years. A key piece of that plan, and the focus of its 2025 work, is a call to action built around the CPS Position Statement. The initiative will encourage and support Hub members' advocacy for the Position Statement recommendations in their respective countries. This effort in turn assists the ongoing efforts of CPS at the United Nations Committee on the Peaceful Uses of Outer Space to influence the development of international space policy. We invite CPS members to reach out to us at community-engage@cps.iau.org if you are interested in participating in our Position Statement campaign.

Additionally, our Hub is looking into putting together a planetarium show focused on satellite constellations, their effects on astronomy, and possible pathways towards solutions. If you have experience with creating planetarium shows, and are interested in contributing to this endeavor, we would be happy to hear from you.

John & Jessica, CE Hub co-leads

In this new series of interviews we speak to CPS members to see what they're working on and what makes them tick. If you're working on something you'd like to share, reach out to us at comms@cps.iau.org.

The night sky is changing. After thousands of years of relative stability, there has been a seismic shift in the way the sky looks. It’s not just astronomers who have noticed this change—astrophotographers have too.

“Six years ago, I would maybe see one satellite flare a night. Now, I see hundreds of them tracking across the night sky,” says Jeff Warner, a member of the CPS and astrophotographer based in Golden, Colorado. “It’s completely changed my relationship with astrophotography. I’m not just hunting vistas anymore—I’m hunting satellite trails.” It's perhaps not surprising: in just five years, some 7,000 constellation satellites have been launched into orbit around our planet.

Starlink 43° and 53° inclination satellites flaring over Mt. Massive, Colorado. The image, taken from east of Mt. Elbert in the San Isabel National Forest near Box Creek, Colorado, shows flaring from satellites orbiting 530km and 540km above the Earth’s surface and took 36 hours to isolate and compile. The flares to the left of the image generally occurred earlier in the photo sequence, while those to the right occurred later. The photograph captures operational Starlink satellites, a recently launched Starlink ‘train’, the Chinese Space Station, various orbiting space debris, and a pair of US Navy Ocean Surveillance System (NOSS) satellites. It vividly illustrates the sheer amount of orbital material now moving through our skies. Copyright: Jeff Warner / CatchingTime.com

The incredible images Jeff produces take 20 to 30 hours to create. He captures hundreds of individual exposures, each around 30 seconds long, over the course of several hours. These are then composited together, with Jeff painstakingly isolating each satellite flare from the background starfield by hand. The result is a breathtaking visual map of seemingly chaotic, yet structured satellite traffic over a small patch of the world, as seen in this image.

“My wife thinks I’m crazy. She asks, ‘Why are you doing this?’ For me, it’s a way of revealing these satellite constellations and giving people a way to relate to the problem visually. I’m trying to create a bridge between the scientific side and the general public. Just reading statistics and seeing data doesn’t make the issue clear for many people. Astrophotography is an amazing tool to engage people with the night sky,” adds Jeff Warner.

The potential of astrophotography as a form of online visual storytelling is undeniable, as demonstrated by Max Alexander's photographic exhibition Our Fragile Space, supported by the CPS, which went on display at the United Nations in Vienna during a COPUOS meeting in 2023 and recently at the UN headquarters in New York.

The Earth’s shadow, as delineated by sunlight reflecting off Starlink satellites passing overhead, captured in Utah on May 6-7, 2024. The image above, taken looking due north from the continental USA, is a composite spanning 4 hours and shows sunlight reflecting off SpaceX’s Starlink satellites orbiting in the 53° inclination orbital shell at 540km altitude. There are currently around 3,368 operational satellites, about half of all Starlink satellites, which orbit the earth between latitude 53° north and 53° south. The bottom-most satellites visible in the center of the image are orbiting over Edmonton, Canada, more than 1600km north of where the photograph is taken from. Copyright: Jeff Warner / CatchingTime.com

Jeff hopes his work can go beyond being just a visual representation of the satellite constellation problem. He envisions it becoming a research tool and is hoping to work more closely with the astronomers who are part of the CPS’ SatHub.

“At the moment, as far as I’m aware, there isn’t a way to gather satellite brightness data from this kind of astrophotography, but it would be amazing if we could do that in the future,” Jeff muses. He is quick to emphasise, however, that “seeing this change has made me more determined than ever to work with the CPS to protect our access to dark and quiet skies in whatever shape that takes.”

Article by Josh Rodden

In this section you will find a selection of recent articles in the media covering the topic of satellite constellations. Feel free to share them with your networks.

Spacenews.com - As the night sky grows crowded, astronomers face a growing problem

Jeff Foust looks at the atmospheric impact of satellite reentries and what's next for space sustainability.

The Washington Post - Space is a human-influenced environment. We need to treat it that way

An opinion piece by the Editorial Board of The Washington Post looking at the growing impact of space debris.

PCMag.com - AST SpaceMobile's Large Satellites to Roll and Tilt to Prevent Astronomy Interference

An article highlighting AST SpaceMobile's efforts to reduce the impact of their BlueBird satellites on ground-based astronomy following coordination with the National Science Foundation (NSF).

BBC Sounds [26min] - The Documentary Podcast: Licence to operate a space object

[free account needed] An audio podcast hosted by astrophotographer Monika Deviat, discussing the loss of the night sky as more satellites are launched, and Indigenous Peoples' perspectives.

News - IAU CPS - UN meeting features satellite impact on astronomy

CPS announcement covering the recent UN COPUOS meeting where the impact of satellite constellations on astronomy was discussed as part of a dedicated agenda item for the first time. You can watch the delegations' statements via the UN Web TV.

Update - IAU CPS - CPS members town hall
At the end of January, the CPS organised its first members town hall meeting. There were updates from the management team, as well as from each of the hubs about their work. In case you missed it, it is now available to watch at the link above.

Resource - ESA - Zero debris technical booklet

The recently-published zero-debris technical booklet published by the European Space Agency includes a chapter proposing solutions to protect dark and quiet skies.