A string of lights that crossed the night sky in parts of the United States on Wednesday, Thursday, and Friday left some people wondering if a fleet of UFOs was coming, but others – mostly amateur astronomers and professional astronomers. – deplored the industrialization of space. .
The Train of Lights was actually a series of low-flying satellites launched by Elon Musk’s SpaceX as part of his Starlink Internet service earlier this week. Callers swarmed television stations from Texas to Wisconsin, reporting the lights and pondering UFOs.
An email to a SpaceX spokesperson was not returned on Saturday, but astronomy experts said the number of lights in rapid succession and their distance from Earth made them easily identifiable as satellites. Starlink for those who are used to seeing them.
“The way you can tell they are Starlink satellites is that they are like a string of pearls, these lights traveling in the same basic orbit, one after the other,” said Dr. Richard Fienberg, Attaché release for the American Astronomical Society.
Fienberg said that satellites that are launched in large groups called constellations follow each other when they are in orbit, especially right after they are launched. The strings get smaller over time.
This month, SpaceX has already launched dozens of satellites. It’s all part of a plan to bridge the digital divide and bring internet access to underserved areas of the world, with SpaceX tentatively scheduled to launch another 120 satellites later this month. In total, the company sent around 1,500 satellites into orbit and requested permission to launch thousands more.
But before the last few years, there were perhaps a few hundred satellites orbiting Earth, mostly visible as individual lights moving across the sky, Fienberg said. The other handful of companies that are planning or launching the satellite constellations have not launched recently and have largely put them into orbit further away from Earth, he said.
Fienberg’s group and others who represent professional and amateur astronomers dislike the proliferation of satellites that can obscure scientific data and ruin a clear night of observation of the universe. The International Astronomical Union issued a statement in July 2019 expressing concerns about the multiple satellite launches.
“The organization, in general, embraces the principle of a dark and radio-silent sky as not only essential for advancing our understanding of the Universe of which we are a part, but also as a resource for all humanity and for the protection of the night. wildlife, ”union representatives wrote. They noted that the reflection of light can interfere with astronomical research, but radio waves can also cause problems for specialized research equipment such as those that captured the first images of a black hole.
Fienberg said there was no real regulation of light pollution from satellites, but SpaceX intentionally worked to mitigate that by creating visors that dampen sunlight reflection from satellites. They have made significant progress in just two years, he said, but many are hopeful that the satellites will someday be at such a low magnitude that they won’t be visible to the naked eye, even at dusk or dawn.
Fienberg noted a massive telescope under construction in Chile, costing millions of dollars and a decade of planning. The telescope will capture a huge part of the sky in the southern hemisphere and take continuous photos to record a kind of film that will show the change in the universe. Due to its size, nearly eight meters in diameter, the massive telescope could also lead to the discovery of darker objects in the night sky, he said.
The plan is for the telescope to start recording in 2023. And with plans for thousands of satellites, Fienberg said it’s hard to imagine they wouldn’t cause problems with the data because there is no way to correct their lights and know how much light needs to be emitted by any fainter object behind the satellites’ path, which could also create ghost images in the data.
“We are now speaking with companies and hope to continue to make progress and eventually when it goes live have tools and techniques to correct lights and possibly weaker satellites,” Fienberg said. . “We cannot say that is wrong and you have to stop because it is about providing internet access to the whole world. It’s an admirable goal, one we would support, if it didn’t mean giving up on something else… the night sky.