A recent study published in Astrophysical Journal Letters has unveiled a controversial plan by the Californian company Reflect Orbital to deploy large mirrors in orbit, designed to reflect sunlight down to Earth after dark. This initiative, which includes the pilot satellite Eärendil-1, aims to illuminate specific areas on the ground, potentially transforming how we utilize nighttime resources.
The Eärendil-1 satellite features an 18 by 18 metre reflector positioned at an altitude of approximately 600 kilometres. It is engineered to project a 2.5-kilometre patch of daylight onto selected locations, catering to needs such as powering solar farms at night or providing light in disaster zones. However, this is merely the beginning; the company envisions a constellation of around 50,000 satellites, with larger models measuring up to 54 by 54 metres.
Measuring Brightness and Impact
Researchers, led by Gáspár Bakos, conducted a thorough analysis of how sunlight reflected from a single mirror would scatter in the atmosphere. They utilized atmospheric physics to model both the direct beam and the surrounding glow produced by Rayleigh and aerosol scattering. The findings are striking: a single 54-metre mirror would appear as a point of light with a magnitude of approximately -16.7, making it about four magnitudes brighter than a full moon.
Moreover, the scattered light would still be detectable from significant distances. Observers standing 14 kilometres away would witness the glow outshining full moonlight across most of the sky, while at 34 kilometres, the brightness would still exceed that of moonlight. If 400 mirrors were operational in the same area, their combined light could be visible from up to 80 kilometres away.
Regulatory Challenges and Public Concerns
The implications of such a project extend beyond mere illumination. The Federal Communications Commission (FCC) approved Eärendil-1 in July, despite receiving over 1,800 public comments and formal objections from the American Astronomical Society and dark sky advocacy groups. The FCC determined that issues related to light pollution and astronomical interference fall outside its regulatory scope, leaving a significant gap in oversight.
This development raises critical questions about who controls the night sky and the consequences for those who cherish its darkness. The potential for widespread light pollution threatens not only amateur astronomers but also migratory birds and nocturnal wildlife, whose behaviors are finely tuned to the natural rhythms of light and dark.
The Future of Our Night Sky
While the launch of a single test satellite does not signify the end of the night sky, it serves as a forewarning of the challenges posed by the commercialization of artificial light. The vision of “sunlight on demand” comes at a cost that may alter the experience of darkness for countless individuals and ecosystems.
This article was produced by NeonPulse.today using human and AI-assisted editorial processes, based on publicly available information. Content may be edited for clarity and style.
