Over the past year, SpaceX has launched hundreds of small, broadband satellites that transmit the Internet in low Earth orbit as part of its Starlink constellation. The count to June: 540.
While the promise of a reliable and fast satellite connection accessible from almost anywhere in the world seems quite promising, not everyone is happy. As a result, small satellites are much brighter than anyone expected, and that’s bad news for astronomers.
In the past few months, countless reports have come up of frustrated astronomers who have ruined their observations by Starlink satellites appearing as bright rays of light.
In the latter case, images taken of the spectacular comet NEOWISE by astrophotographer Daniel López were “completely photographed by Elon Musk’s Starlink satellites,” as astronomer from the Space Telescope Science Institute Julien Girard noted in a tweet.
17 30-second images of the comet added by @cielodecanarias, completely photographed by @elonmusk’s #Starlink satellites. There are a few hundred of them right now, there will be a few thousand in the near future. @SpaceX agrees to coat them to better target them, but still … pic.twitter.com/TYtTf5xwhc
– Julien Girard (@djulik) July 22, 2020
“If there are a lot of bright moving objects in the sky, it greatly complicates our work,” said Smith College astronomer James Lowenthal. The New York Times last November. “It potentially threatens the science of astronomy itself.”
They are so bright, in fact, that some are visible to the naked eye. In fact, viewers continue to mistake them for UFOs, according to December news reports.
The brightness is due in part to the fact that Starlink satellites are orbiting Earth at a much closer distance than most, an operating altitude of approximately 550 kilometers, rather than the usual orbit of Middle Earth (20,000 km). or the geostationary orbit (36,000 km) used by other types of satellites, such as those that provide GPS and communication services.
SpaceX has also claimed that they are brilliant from the start because they are still scaling in orbit after launch, and will eventually spread and dim over a period of several months.
Fortunately, SpaceX claims that it is working on a number of solutions.
The first attempts to paint the bottom of each satellite with a coat of anti-reflective paint appear to have been only partially successful.
SpaceX is now testing a new method: launching satellites with a pair of cool sunglasses. The space company plans to mount retractable umbrellas, called “VisorSat,” on each of the satellites to prevent sunlight from hitting their reflective parts, the main reason they are so bright. Spacenews reported in May.
The company’s latest batch of Starlink satellites, which launched in June, included a single unit with this parasol. It is not yet clear if the solution will appease astronomers.
SpaceX’s most recent launch on Starlink, 57 satellites equipped with a VisorSat hood, had to be delayed due to weather earlier this month. The launch is now scheduled for July 29.
If no solution is found, astronomers could be struggling with bright Starlink satellites that will ruin their observations for many years. SpaceX already has permission from the Federal Communications Commission to launch tens of thousands of Starlink satellites to provide global Internet coverage to the world.
More about Starlink: SpaceX is now receiving beta tester requests from Starlink
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