(CNN) -- SpaceX has launched at least 120 Starlink satellites into orbit since May. But astronomers say they've already seen their fears of sky obstruction come to fruition.
Clarae Martínez-Vázquez, an astronomer at Cerro Tololo Inter-American Observatory in Coquimbo, Chile, tweeted that the bright lights reflected by the satellites interfered with a high-powered camera used to observe other galaxies.
"Wow!! I am in shock!! The huge amount of Starlink satellites crossed our skies tonight at [the observatory]," she said. "Our DECam exposure was heavily affected by 19 of them! The train of Starlink satellites lasted for over 5 minutes!! Rather depressing... This is not cool!"
SpaceX CEO Elon Musk started developing the project in 2015 to boost internet connection on the ground. The hope is that more satellites will expand bandwidth and coverage.
But astronomers fear that the more crowded low Earth orbit becomes, the more light will interfere with their telescopes' observations.
Satellites on Earth
Satellites can be visible from Earth, thought they're usually quite faint. But when their panels reflect a "burst" of sunlight back to Earth, they can appear brighter for a brief period, according to National Geographic.
Those streaks of bright light can obstruct the astronomical objects just underneath them and could trigger false signals in telescopes, Nature reported.
In March, the Union of Concerned Scientists reported that there are currently more than 2,000 satellites in orbit, though that count didn't include the Starlink satellites.
The most visible, like the International Space Station, are in low Earth orbit, and are easier to spot in the summer, when the sun shines for longer periods -- thus, satellites have more time to reflect it.
And many, many more satellites could join those already in orbit. SpaceX has permission from regulators to launch more than 10,000 satellites, and recently requested adding 30,000 more.
In response to the initial uproar in May, Musk asserted that the Starlink satellites wouldn't impact astronomical observations.
"There are already 4,900 satellites in orbit, which people notice ~0% of the time," he tweeted. "Starlink won't be seen by anyone unless looking very carefully & will have ~0% impact on advancements in astronomy."
Reached by CNN on Wednesday, a SpaceX spokesperson responded that it is speaking with leading astronomy groups to find ways that the satellites won't disrupt their work. On a more tactical level, it's also making the base color of Starlink satellites black, which it hopes will help. If it needs to, SpaceX says it can adjust some of the satellites' orbits, too.
In other words: they're listening.