Our view of the cosmos is rapidly changing. A single two-hour photographic experiment by New Zealand astrophotographer and teacher Brendan Larsen captured more than 14,000 satellite trails slicing across the stars, underscoring just how busy Earth’s orbital neighborhood has become. Below, we unpack how the image was made, why so many trails now dominate long-exposure photos, and what this means for science, stargazing, and the future of space.
The Experiment: 578 Frames, One Patch of Sky
Larsen aimed his camera at a fixed region of the southern sky for exactly two hours, collecting 578 individual 15-second exposures. By stacking the frames, every passing object brighter than magnitude +6 left a linear imprint. When the composite was finished, the software counted roughly 14,000 distinct streaks, each one a satellite or spent rocket body reflecting sunlight.
To put that in perspective: two decades ago, photographers attempting the same experiment would have recorded only a few dozen traces in the same time span. The explosive uptick is largely due to the rise of megaconstellations—fleets of hundreds or even tens of thousands of small, low-Earth-orbit (LEO) satellites designed for global broadband coverage.
Where All Those Satellites Came From
• As of late 2023, humanity has launched roughly 8,000 active satellites, with about 6,000 residing in LEO.
• SpaceX’s Starlink accounts for more than 5,000 of them and holds regulatory approval for up to 12,000, with a long-term filing that could reach 42,000.
• Other operators—OneWeb, Amazon’s Project Kuiper, China’s GuoWang, and multiple national programs—plan fleets numbering in the thousands.
At orbital altitudes between 300 km and 1,200 km, these spacecraft circle Earth every 90–120 minutes. Shortly after sunset and just before sunrise, they are still sun-lit while the ground is dark, creating the bright lines that showed up in Larsen’s photograph.
Why Astronomers Are Worried
Optical astronomy: Long-exposure images from survey telescopes like the Vera C. Rubin Observatory can be marred by hundreds of streaks per frame, complicating searches for faint galaxies, supernovae, or potentially hazardous near-Earth asteroids.
Radio astronomy: Constellations transmit in bands adjacent to or overlapping with those used for cosmic observations, risking interference that can drown out faint celestial signals.
Data dilution: Removing satellite trails from raw images is time consuming and not always perfect; residual artifacts can masquerade as astrophysical phenomena or wipe out genuine detections.
Possible Mitigations
• Darker coatings & sunshades: Operators are experimenting with less reflective surfaces and visor-like attachments to cut brightness.
• Orbital coordination: International bodies such as the IAU and ESA advocate for altitude and inclination spacing to reduce cluster congestion.
• Software filtering: AI-based streak removal tools can reclaim some scientific value, though they cannot restore lost photons.
• Regulation: Agencies in the U.S., U.K., and Europe are drafting thresholds for acceptable optical and radio brightness.
Beyond Science: Cultural and Environmental Concerns
Humanity’s relationship with the night sky is older than recorded history. For many Indigenous cultures, stellar patterns are storybooks, calendars, and navigation aids. A sky peppered with moving dots can erode this intangible heritage.
Additionally, every launched satellite eventually becomes orbital debris. Although current megaconstellation craft are designed to de-orbit within five years of retirement, failures occur, and cumulative risk grows with each new batch lofted into space.
What You Can Do
• Support dark-sky initiatives: Organizations like the International Dark-Sky Association lobby for responsible lighting and satellite brightness standards.
• Participate in citizen science: Projects such as SatNOGS and Globe at Night rely on volunteer observations to track satellites and measure sky clarity.
• Stay informed: Public comment periods at national regulators (e.g., the U.S. FCC, New Zealand MBIE) allow citizens to weigh in on proposed launches and licensing thresholds.
Looking Up—And Forward
Brendan Larsen’s dramatic mosaic captures just one evening above New Zealand, yet it mirrors a global transformation. The race for satellite-based connectivity promises economic and humanitarian benefits but challenges our ability to observe—and simply enjoy—the universe beyond Earth. As deployment accelerates, balanced policy, innovative engineering, and public engagement will determine whether tomorrow’s skies remain a canvas for stars or become dominated by our own technological footprints.
