|The faraway star KIC 8462852 has been a fervent topic of debate over the last few months, ever since folks at SETI proposed that maybe—just maybe—a there was a giant alien megastructure around the star responsible for the weird readings scientists had been getting. Since then, most people have come to accept the more ordinary explanation that comets are responsible for the space oddity. But it turns out the NASA’s next great observatory, the James Webb Space Telescope, could be just the thing to answer this kind of question for sure.|
The hubbub all started last October when NASA’s Kepler planet-hunting telescope found a strange phenomenon around a sun-like star. Something was blocking out 20 percent of the light from KIC 8462852, since nicknamed “Tabby’s Star” after discoverer Tabetha S. Boyajian. A planet even the size of Jupiter or larger should have blocked out only 1 percent of the light. That suggests something big is here, and no Earth-based telescopes detected heat coming from whatever was blocking the light, meaning it wasn’t a planet or an asteroid.
The lead hypothesis has been, and remains, that comets are blocking out the light. A swarm of them may have collided and created a giant cloud of icy-cold debris. But even that doesn’t quite tell the whole story. For one thing, astronomers still can’t explain how there would be a cloud of comets big enough to block out that much light from a mid-sized star. It would require more mass than is found in our solar system’s entire Kuiper Belt, the region of objects that includes Pluto, an unlikely scenario.
That’s where the megastructures came in […]