In 2015, astronomer Tabetha Boyajian and her colleagues reported on a star 1,400 light-years away that occasionally dimmed. Actually, it dimmed a lot, and this wasn’t normal stellar behavior. One explanation was that the star was surrounded by a Dyson sphere. The idea, proposed years ago by physicist Freeman Dyson, is that really advanced aliens would construct a gargantuan, spherical swarm of solar panels in orbit beyond their own planet gathering enough starlight to energize the aliens’ terrestrial lifestyles, and could sometimes get in the way of light from the star, causing it to intermittently dim as seen from afar.
SETI has asked “is looking for radio signals from alien civilizations really the best plan? Is it possible that we’re making the wrong bet.” In nearly every radio SETI experiment, the amount of time spent listening at any given frequency is but a few minutes. Meanwhile, the universe has been around for nearly ten thousand trillion minutes. Picking up an alien civilization’s transmissions requires that the signal reach your telescope at the very moment that you’re pointing it in their direction –SETI’s well-known “synchronicity” problem.
If you’re not sure you’re the Milky Way’s top-dog society, suggests SETI’s senior astronomer, Seth Shostak, you don’t want to bet the farm by assuming that the alpha aliens, wherever they might be, have good intentions after they receive your radio signals. Silence could have huge survival value.
So SETI is proposing that we search for physical artifacts, alien structures, massive engineering works that an advanced society has constructed somewhere in space.
Something akin to Elon Musk’s SpaceX plans to launch thousands of satellites, each of which carries a solar panel that not only gathers sunlight but also reflects it back to Earth — creating a mega-constellation of false stars collectively called Starlink that will connect the entire planet to the internet. The problem in addition to the sheer quantity of artificial objects clutter the night sky is their brightness .
Elon Musk, SpaceX’s founder and chief executive, has offered assurances that the satellites will only be visible in the hours after sunset and before sunrise, and then just barely. But the early images posted on Twitter revealing a train of spacecraft as bright as Polaris, the North Star, shown above that has led many scientists to question his assertions. “This has the potential to change what a natural sky looks like,” Tyler Nordgren, an astronomer who is now working full-time to promote night skies, told Shannon Hall at the New York Times.
And Starlink will some have competition further blocking the view of our cosmos enjoyed by Homer’s Odysseus as he sailed the ancient Agean from Amazon, Telesat and OneWeb, who are launching into the space internet business making satellites nearly as plentiful as cellphone towers.
While private companies see major business opportunities in low-Earth orbit and beyond, many astronomers fear that space will no longer be “the province of all mankind,” as stated in the Outer Space Treaty of 1967 reports Hall.
And while a press officer at SpaceX told the New York Times that “the satellites will grow fainter as they move to higher orbits, some astronomers estimate that they will be visible to the naked eye throughout summer nights affecting their research. The satellites can even “flare,” briefly boosting their brightness to rival that of Sirius, the brightest star in the sky, when their solar panels are oriented just right.”
Another astronomer fears that the Large Synoptic Survey Telescope — an 8.4-meter telescope under construction on a Chilean mountaintop that will soon scan the entire sky — might have to deal with one Starlink satellite in every couple of images it takes during the first few hours of twilight.
“We’re really at that point where we have to assess what we’re going to do,” said Ronald Drimmel, an astronomer at the Turin Astrophysical Observatory in Italy.
The Starlink satellites also emit radio frequencies which could interfere with radio telescopes in radio quiet zones in remote locations far from cell towers and radio stations. Moreover, reports Shannon Hall, some astronomers are worried “that Starlink plans to operate on two frequency ranges that astronomers use to map the gas throughout the universe — allowing them to see how planets as large as Jupiter assemble, and how galaxies formed immediately after the Big Bang.”
“If those frequency channels become inaccessible, it’s extremely limiting to what we can learn about the early universe,” said Caitlin Casey, an astronomer at the University of Texas at Austin.
“The idea that one or two people somewhere in some country in some boardroom can make the decision that the constellations hereafter will suddenly be fluid, and move from night to night and hour to hour — well, I don’t think that’s their decision to make,” Nordgren concluded.
Perhaps some distant civilization in the far reaches of the Milky Way will detect the Stalink “Constellation” surrounding a faint blue dot of a planet orbiting a mid-sized star. How would our sophisticated Internet Era human population react to an encounters with a more technologically advanced civilization?
”One such encounter occurred during the 19th century,’ observed Liu Cixin, China’s foremost science fiction author and philosopher of first contact, “when the ‘Middle Kingdom’ of China, around which all of Asia had once revolved, looked out to sea and saw the ships of Europe’s seafaring empires, whose ensuing invasion triggered a loss in status for China comparable to the fall of Rome.”
The “appearance of this Other” might be imminent, warns the author of The Three-Body Problem, and that it might result in our extinction. “Perhaps in ten thousand years, the starry sky that humankind gazes upon will remain empty and silent,” he writes in the postscript to one of his books. “But perhaps tomorrow we’ll wake up and find an alien spaceship the size of the Moon parked in orbit.”