Before Starlink launched, SpaceX coordinated with the National Science Foundation and its radio-astronomy observatories to make sure there wouldn’t be any overlap. Unfortunately for optical astronomers, there is no such framework when it comes to the brightness of satellites—no international body in Geneva, let alone a dedicated agency in the United States. The Federal Communications Commission’s regulatory realm spans communication networks across multiple industries, which means its oversight includes, oddly enough, both satellites and offensive Super Bowl commercials. But while American satellites need the agency’s permission to launch, the FCC does not regulate the appearance of those satellites once they’re in orbit.
Read: The dark side of light
From the ground, Starlink satellites appear as points of light moving from west to east, like a string of tiny pearls across the dark sky. (Some people have even mistaken them for UFOs.) The satellites are at their brightest after launch, before they spread out and rise in altitude, and are visible even in the middle of cities. They appear dimmer after a few months, when they reach their final orbit, about 342 miles (550 kilometers) up, but even then they can still be seen in darker areas, away from the glare of light pollution.
In the months since they first launched, the Starlink satellites have been essentially photobombing ground-based telescopes. Their reflectiveness can saturate detectors, overwhelming them, which can ruin frames and leave ghost imprints on others. Vivienne Baldassare’s work depends on comparing images taken night after night and looking for nearly imperceptible variations in light; the slightest shifts could reveal the existence of a black hole at the center of a glittering, distant galaxy. Baldassare, an astronomer at Yale, can’t see behind the streak of a satellite. “You can’t just subtract that off,” she says. Some objects, such as comets, are better viewed during dawn and dusk, when there’s just enough sunlight to illuminate them. But because they orbit close to Earth, the Starlink satellites can be seen during these hours, too; imagine missing a comet as it passes uncomfortably close to Earth because of too many satellites.
SpaceX is “actively working with leading astronomy groups from around the world to make sure their work isn’t affected,” says the company’s spokesperson, James Gleeson. To that end, one satellite in a batch of 60 launched in early January with experimental coating that might make it less reflective. Engineers won’t know how well it worked until the satellite reaches its final orbit.
As it waits for those data, SpaceX has continued to launch dozens of the original satellites. The company wants to deploy more than 1,500 satellites in 2020 alone, which means launches could come every few weeks. On top of those, the company OneWeb is scheduled to launch a batch of its own internet satellites this week; the proposed constellation of about 650 will fly at higher altitudes, which might have the paradoxical effect of being too dim to see from the ground but bright enough for telescopes to spot well into the night. And Jeff Bezos’s Amazon has asked the FCC for permission to someday launch a network of 3,200 internet satellites. In a few years’ time, three companies alone might transform the space around Earth, with SpaceX leading the pack.