light pollution

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Dark Hours
14 hours ago
- The visibility window for good nights in Madison opens at 22:21 and is usable only if you stay local.
- Good nights are rare, clustered, and easy to miss; alerts require leaving an email for notification when launched.
- Submitted data (email and approximate location within ~10 km) is stored for planning and can be unsubscribed with one click.
- Sky conditions depend on light pollution: thin skies allow viewing only bright targets, and the best moment is hindered by Madison's light pollution.
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We're Thinking About Darkness All Wrong
7 days ago
- Haleakalā National Park offers one of the darkest skies on Earth, ideal for astronomy tours led by Serena Wurmser, who emphasizes the stars as a universal connection.
- Light pollution affects 99% of Americans, causing the sky to brighten 10% annually, with artificial light reaching even remote natural areas like Death Valley and Haleakalā.
- Health consequences of light pollution include sleep disturbances, depression, obesity, diabetes, and a 14% increased breast cancer risk as shown in a Harvard study.
- Artificial light at night (ALAN) creates 'evolutionary traps' for animals like sea turtles mistaking hotel lights for the moon, leading to fatal collisions with cars.
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What Did We Lose When We Lost the Stars
14 days ago
- The essay reflects on the profound loss of experiencing the starry night sky due to artificial light and modern technology, framing it as a cultural, spiritual, and environmental tragedy.
- Historical figures like Dante illustrate how stars were once central to human consciousness, serving as guides and sources of wonder, contrasting with today's widespread light pollution.
- Technological advances, especially electrification and projects like Starlink satellites, have replaced the natural sublime with a technological sublime, eroding our connection to darkness and the cosmos.
- The loss of darkness and stars represents the transformation of a public commons into a luxury commodity, exemplified by dark-sky tourism, highlighting issues of access and privilege.
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U.S. approval of giant 'space mirror' satellite alarms astronomers
17 days ago
- A California startup, Reflect Orbital, received FCC approval to launch its test satellite Eärendil-1, which uses a steerable mirror to beam sunlight, aiming to provide 'sunlight on demand'.
- The company plans to launch up to 50,000 similar satellites by 2035, but astronomers fear they will cause severe light pollution, potentially making the night sky three to four times brighter globally.
- Critics argue the FCC's regulatory scope is limited, ignoring optical concerns like eye damage, disrupted circadian rhythms for wildlife, and hindering astronomical observations.
- There's no U.S. regulatory body besides the FCC to enforce the Outer Space Treaty's 'harmful contamination' clause before damage occurs, leading to calls for new oversight mechanisms.
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The US Approves Launch of Mirror Satellite That Can Reflect Sunlight at Night
19 days ago
- US FCC approved Reflect Orbital's experimental mirror satellite, Eärendil-1, on July 9.
- Eärendil-1 will reflect sunlight to specific Earth locations for potential uses like solar energy extension, emergency lighting, and remote construction.
- The project faces criticism from astronomers and environmental groups over light pollution, impacts on ecosystems, and aviation safety.
- Reflect Orbital envisions a future constellation of 50,000 satellites by 2035, raising concerns about sky transformation and astronomical interference.
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FCC Approves Reflect Orbital's Space Mirror Satellite
20 days ago
- The FCC approved Reflect Orbital's plan to launch Earendel-1, a test satellite with a 60x60 foot steerable thin-film reflector, to reflect sunlight to Earth for applications like powering solar farms at night or aiding in disaster relief.
- Despite over 1,800 public objections and concerns from environmental groups and astronomers about potential light pollution, eye damage, and impacts on scientific research, the FCC granted approval based on encouraging new technology under the Communications Act and limited the scope to a single demonstration satellite.
- The FCC stated that concerns about the solar reflector fall outside its authority over radiofrequency spectrum, and any risks are outweighed by the public interest benefits of testing the technology, while noting it cannot conduct environmental reviews for satellite operations beyond its statutory mandate.
- Critics, including Dark Sky UK, argue this reveals a regulatory gap in assessing satellite impacts on the environment and sky, with calls for the FCC to review large constellations, but Reflect Orbital plans to launch Earendel-1 this year and conduct independent research on its technology's effects.
FCC Approves Reflect Orbital's Space Mirror Satellite That Astronomers Hate
23 days ago
- The FCC approved Reflect Orbital's launch of a single demonstration satellite, Earendil-1, using a 60ft by 60ft steerable thin-film reflector to test reflecting sunlight to Earth.
- The approval faced over 1,800 public objections, citing risks like eye damage to astronomers, flash blinding of drivers and pilots, and negative impacts on scientific research.
- The FCC justified approval by stating it encourages new technologies, concerns are unrelated to its radiofrequency authority, and environmental review is beyond its statutory mandate.
- Critics argue this highlights a regulatory gap, as the FCC lacks authority to assess environmental impacts, raising questions about who oversees satellite effects on skies and Earth.
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Study: ultra-black coating could reduce satellite light pollution
a month ago
- Astrophysicists at the University of Surrey propose using Vantablack® 310, an ultra-black coating, to reduce satellite brightness and light pollution.
- The coating reflects only about 2% of light, distributing it diffusely to minimize bright streaks and flares that interfere with astronomical observations.
- Simulations show the coating can make satellites significantly fainter, nearly meeting International Astronomical Union brightness limits for protecting the night sky.
- The research is part of the Light Pollution and Sustainable Space initiative, which won a sustainability award and includes an upcoming in-orbit demonstration on the Jovian-1 CubeSat mission.
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No more than 100 000 faint satellites should orbit Earth
a month ago
- A new ESO study warns that current proposals to launch over 1.7 million satellites, including extremely bright ones, would have 'devastating consequences for astronomy'.
- The study suggests that to protect astronomical observations, no more than 100,000 faint satellites (below naked-eye visibility) should orbit Earth.
- SpaceX plans to send one million more satellites for space-based data centers, and Reflect Orbital aims to launch 50,000 large mirror-like satellites by 2035 to provide sunlight at night.
- Simulations show that satellite constellations would create bright trails in telescope images and increase overall sky brightness, with Reflect Orbital's full fleet making the sky up to 3–4 times brighter.
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light pollution

Dark Hours

We're Thinking About Darkness All Wrong

What Did We Lose When We Lost the Stars

U.S. approval of giant 'space mirror' satellite alarms astronomers

The US Approves Launch of Mirror Satellite That Can Reflect Sunlight at Night

FCC Approves Reflect Orbital's Space Mirror Satellite

FCC Approves Reflect Orbital's Space Mirror Satellite That Astronomers Hate

Study: ultra-black coating could reduce satellite light pollution

No more than 100 000 faint satellites should orbit Earth