Space mirrors could ruin astronomy — and your eyes
The dream of space mirror projects is to provide solar energy, day or night. Futurists have envisioned satellite mirrors reflecting the sun's light to Earth for over a century. Russian scientists experimented with the concept in the '90s with the Znamya project. The idea is to place a large mirror in orbit and angle it to reflect sunlight onto specific areas for illumination or solar power generation.
Now, Reflect Orbital, a California-based company, aims to launch a test satellite named Eärendil-1, a precursor to a fleet of up to 50,000 space mirrors. The 18-square-meter mirror satellite has been approved for launch by the Federal Communications Commission (FCC) and will create a 5-kilometer-wide beam of light. This beam could be used for solar energy capture, boosting agricultural yields, or search and rescue operations during nighttime emergencies.
However, the consequences are alarming. The satellite will be strikingly bright, as bright as Venus from outside the beam and four times as bright as the Moon within the beam. This brightness poses significant risks to astronomy and public safety.
Astronomers express concern as the satellite's brightness could disrupt scientific observations and cause permanent eye damage to anyone using telescopes, including amateur astronomers. Light pollution, already a threat to human well-being and local ecosystems, would worsen with space mirrors. The overall brightness of the night sky would rise due to atmospheric scattering, making it impossible to observe distant objects or spot Earth-threatening asteroids.
Reflect Orbital acknowledges the risk but argues that it will work to avoid astronomical facilities and has engaged with stakeholders. However, the company hasn't disclosed specific exclusion zones or plans to warn the public about potential dangers. Critics argue that the company hasn't done its due diligence, and the lack of regulation around satellite technologies exacerbates the issue.
The problem extends beyond one company's satellite. The absence of regulation around potentially harmful satellite technologies raises concerns about human, environmental, and astronomical impacts. The FCC's stance on astronomical concerns and the voluntary nature of the Office of Space Commerce's certification program leave a regulatory void. The need for renewable energy is undeniable, but astronomers question the trade-off of tens of thousands of extremely bright satellites in the night sky.
Alternative avenues for solar power generation exist, and they don't require damaging the night sky or harming nearby ecosystems. The loss of the Milky Way and starry skies is a concern for astronomers and the public. The IAU and Slovakia have proposed banning space mirrors if strong oversight measures cannot be implemented to protect eye safety and astronomical research.
In conclusion, while the benefits of space mirrors for renewable energy are significant, the potential risks to astronomy and public safety cannot be ignored. A balanced approach is necessary to ensure that technological advancements do not come at the expense of our natural heritage and the well-being of future generations.
