Many stars may turn permanently invisible to our eyes due to rapid increases in satellite launches, according to research from a team of Canadian professors.
A model created by professors Samantha Lawler at the University of Regina, Hanno Rein at the University of Toronto and Aaron Boley at the University of British Columbia project the consequences of sending dozens of communications satellites into orbit every two weeks.
Lawler said Starlink, a satellite internet constellation operated by Elon Musk’s private U.S. aerospace company SpaceX, launched nearly 2,000 of the 3,500 satellites currently in orbit within the last year. She added the U.S. Federal Communications Commission currently permits SpaceX to launch up to 42,000 satellites and SpaceX’s bimonthly launches of 60 satellites could eventually increase tenfold.
“It’s going to be very disorienting when there are a couple hundred of these that are all moving in different directions across the sky, through the stars,” said Lawler, who teaches astronomy.
About 200 satellites will be visible to the naked eye at 50 degrees latitude by next summer, based on Lawler’s model of 65,000 satellites launched between four companies. She said only about 4,000 stars are visible to us at any given time and that the number will drop with increased light pollution.
“We up here see a lot more of those satellites illuminated at night compared to areas further south, near the equator, where there are going to be long periods during the night where there are no satellites visible,” said Rein, who teaches physical and environmental sciences.
Satellites are most noticeable as they travel through lower orbit after launch. Lawler said companies are not required to dim or disclose the brightness of their satellites.
This has been a concern since the 1990s, when companies like Microsoft first considered building large satellite constellations, according to Hugh Lewis, an engineering and physical sciences professor at the University of Southampton in the U.K.
“We could get to a situation where most of the points in the sky could be satellites and other bits of junk that are up there,” Lewis said.
He said satellites are often “orders of magnitude brighter” than the stars we observe and that SpaceX has installed vizors to reduce sunlight reflected off satellites.
Lewis also said SpaceX’s initial target altitude of about 1,200 km was also reduced by half because of the “tens of thousands of years” it would take for failed satellites to decompose at higher altitudes.
The slow decomposition of satellites is also concerning because of the possibility of collisions.
Kessler syndrome, the issue of satellite collisions causing increased space debris, can result in countless satellite fragments blasting through orbit at several kilometers a second, according to Lawler. She said solar flares, which occur every 11 years as part of the sun’s activity cycle, have the potential to shut down satellites and add to Kessler syndrome’s cascade effect.
The last major collision in orbit was in 2009, according to Lewis.
“One of the biggest fears I get for these large constellations is not just the impact on the night sky,” he said. “It’s the impact on the safety and sustainability of our future in space.”
Lewis said he hopes public awareness on this matter will lead to better-informed decisions when it comes to internet service providers.
While Lawler reasoned broadband internet to be a major issue for remote communities in the Northwest Territories, she said alternate solutions such as cell tower networks would lessen reliance on SpaceX, which provides satellite internet access to much of the world via Starlink.
“There’s obviously a great need for cheap and reliable fast internet access all around the world, including in Canada,” Rein said.
As he explained, however, broadband internet considered affordable for many Canadians will still be unattainable for many others around the world.
Among Rein’s concerns is who will be responsible for a company’s space debris in the case of bankruptcy.
“Cleaning up a mess in the first place, with current technology, is not possible,” he said. “You cannot fly up there and collect 300,000 satellites, each individually, and bring them back to Earth if they’re no longer responding.”
For Lawler, growing satellite numbers also raise concerns for future astronomical research.
“When we lose observing capabilities, we lose theoretical capabilities also.”
She said she hopes to see international regulations put in place for satellite protocols as well as more consultation with astronomers.
“From a bigger point of view, it not only affects astronomy,” Rein said. “These new satellites will just visually change how the night sky looks … for all the people around the world.”