An ambitious proposal by US startup Reflect Orbital has astronomers and environmentalists deeply concerned.\u00a0<\/p>\n
The California-based company plans to deploy a massive constellation of satellites designed to beam \u201csunlight on demand\u201d to Earth. It could extend the operating hours of solar farms even into the dark.\u00a0<\/p>\n
Although the project offers novel renewable energy solutions, critics caution that it could alter the night sky by creating light pollution.<\/p>\n
Bloomberg<\/a> reported that the constellation\u2019s light could be \u201cblindingly bright\u201d for sensitive astronomy cameras and potentially \u201cruinous\u201d to optical astronomy conducted from the ground.<\/p>\n Test satellite launch in 2026<\/p>\n Reflect Orbital\u2019s vision involves orbiting mirrors reflecting sunlight down to specific locations on Earth. <\/p>\n The satellites will use mirrors made from Mylar, a durable, ultra-thin material, to capture sunlight and direct it to targeted spots on the ground.<\/p>\n If successful, this technique could enable solar farms to generate power<\/a> even after the sun has set.<\/p>\n The company has already applied to launch its first 18-meter test satellite, named Earendil-1, in 2026. The launch license has been requested<\/a> from the Federal Communications Commission.\u00a0<\/p>\n Current reports indicate that the test satellite would be followed by a constellation of roughly 4,000 orbiting satellites by 2030.\u00a0<\/p>\n The satellites are expected to orbit about 625km (388 miles) above the ground.\u00a0<\/p>\n As per the Conversation<\/a> piece, it\u2019s possible that the constellation could eventually swell to include 250,000 satellites, all potentially fitted with 54-meter mirrors. <\/p>\n These satellites will reflect light roughly 15,000 times dimmer than the midday sun but remain brighter than a full moon.<\/p>\n A looming threat to dark skies<\/p>\n Astronomers are particularly alarmed by the project\u2019s implications.\u00a0<\/p>\n The existing satellites<\/a> cause light pollution as an unintended byproduct of reflecting sunlight, but Reflect Orbital\u2019s satellites are designed for precisely that purpose.\u00a0<\/p>\n \u201cEven if just the test satellite works as planned, it will sometimes appear far brighter than the full moon,\u201d warned<\/a> one expert. \u201cA constellation of such mirrors would be devastating to astronomy and dangerous to astronomers.\u201d<\/p>\n The concerns are multifaceted.\u00a0<\/p>\n Looking through ground telescopes like Rubin, the brightness of these mirrors could nearly match the sun\u2019s surface, posing a risk of \u201cpermanent eye damage<\/a>.\u201d<\/p>\n Furthermore, the constellation brightness would drown out faint celestial objects and limit astronomical observations.<\/p>\n Beyond astronomy, the continuous illumination could disrupt the delicate daily rhythms of nocturnal animals, impacting ecosystems worldwide.\u00a0<\/p>\n Critics also point out that even though Reflect Orbital intends to illuminate targeted areas, the satellites\u2019 movement will cause the light beams to sweep over large regions of Earth, inevitably. It could produce flashes in the night sky that are brighter than the moon.<\/p>\n Feasibility under scrutiny<\/p>\n Apart from the light pollution concerns, the physics of reflecting sunlight from orbit reveals major challenges to Reflect Orbital\u2019s plan.\u00a0<\/p>\n Since low-Earth orbit satellites pass over a location in only about 3.5 minutes, maintaining continuous illumination for even one hour demands thousands of satellites.\u00a0<\/p>\n Reflect Orbital\u2019s own staggering projection of 250,000 satellites still calculates to only delivering the target 20% of midday sun to a very limited number of regions simultaneously.<\/p>\n The company asserts that it will redirect sunlight in a manner that is \u201cbrief, predictable, and targeted,\u201d and promises to share satellite location data to help observatories avoid disruption.<\/p>\n The American Astronomical Society\u2019s August survey revealed that the majority of astronomers believe the proposed satellite constellation would negatively impact their work.<\/p>\n The number of satellites cluttering Earth\u2019s orbit is rapidly increasing, primarily due to large constellations launched by private companies like SpaceX<\/a> (Starlink), Amazon (Project Kuiper), and Eutelsat OneWeb. <\/p>\n