19.09.2022

Increase in low-orbit satellites prompting concerns over interference with observing sky, spotting asteroids

It was an unusually starry night in Kitimat, B.C., Tuesday when Lois Godfrey saw a trail of light move through the sky.

Godfrey spotted the star-like object around 9:15 p.m. while on a walk with her husband — one of more than 40 they saw that night, moving eastward in a straight line, she says.

"I happened to look up as we turned the corner into the dark space, and noticed a string of lights like little pearls dancing across the sky," she said.

"You couldn't miss them."

Godfrey is one of many in B.C. who have seen trains of satellites being launched into space by SpaceX, the California-based spacecraft manufacturer founded by Elon Musk in 2002.

During the first two years of the project, residents of Eastern Canada — in places such as Newfoundland, Ontario and New Brunswick — observed the satellites above them.

More recently they've been spotted in B.C., with sightings from Vancouver Island to northern B.C., according to a website that tracks their visibility.

Since 2019, SpaceX has launched more than 3,000 communications satellites into orbit for its Starlink network, at an altitude of about 550 kilometres, to provide internet services to remote and rural areas around the world.

Traditional telecommunications satellites generally orbit more than 20,000 kilometres above earth, but Starlink's are lower in order to reduce network latency and delays.

Last weekend, the company launched 34 Starlink satellites from the Kennedy Space Center in Florida, according to its website. SpaceX says it plans to launch an additional 40,000 satellites in upcoming years.

Concerns for the night sky

But the increase in low-orbit satellites has prompted concerns from astronomers the world over who note the bright objects make it more difficult for people to observe other objects in the sky, including stars and distant planets.

Malhar Kendurkar, president of the Prince George Astronomical Society, says one of his key worries is that the satellites could interfere with astronomers' ability to see other near-earth objects such as asteroids, which could pose a risk should they collide with the planet.

In 2013, for example, a meteor over Russia injured more than 1,000 people as it exploded over western Siberia.

Kendurkar said that although the probability of such events is "quite low," it is still crucial to be able to spot such objects before they enter our planet's atmosphere.

The Paris-based International Astronomical Union (IAU) has expressed similar concerns. In 2019, the union said in a statement that satellite constellations built with highly reflective metals "can be detrimental to the sensitive capabilities of large ground-based astronomical telescopes."

Earlier this year, the IAU announced the formation of the Center for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference.

Their goal is to push for the regulation of the number of satellites private companies can launch over the earth in an effort to preserve people's ability to see the night sky.

There are also worries about collisions and pileups, resulting in the satellites crashing to earth.

In February, several Starlink satellites re-entered the atmosphere after being struck by a solar storm.

Quelle: CBC News