Back in October, findings from the Kepler Space Telescope suggested that something strange was going on around a star called KIC 8462852. Kepler was built to detect exoplanets by measuring the cycles of dimming light from other stars, indicating that a large object was passing between them and Earth. But the dimming light cycle from KIC 8462852 seemed to suggest a lot of smaller objects swarming around it. Scientists narrowed down the explanations to either a swarm of comets or alien megastructures. Tuesday, NASA announced evidence garnered by two other telescopes that pointed to the comet explanation.
First, the space agency pointed the WISE or Wide-Field Infrared Survey Explorer at KIC 8462852.
“One way to learn more about the star is to study it in infrared light. Kepler had observed it in visible light. If a planetary impact, or a collision amongst asteroids, were behind the mystery of KIC 8462852, then there should be an excess of infrared light around the star. Dusty, ground-up bits of rock would be at the right temperature to glow at infrared wavelengths.
“At first, researchers tried to look for infrared light using NASA’s Wide-Field Infrared Survey Explorer, or WISE, and found none. But those observations were taken in 2010, before the strange events seen by Kepler — and before any collisions would have kicked up dust.”
Then, NASA turned to the Spitzer telescope which, like WISE, detects infrared light.
“But, like WISE, Spitzer did not find any significant excess of infrared light from warm dust. That makes theories of rocky smashups very unlikely, and favors the idea that cold comets are responsible. It’s possible that a family of comets is traveling on a very long, eccentric orbit around the star. At the head of the pack would be a very large comet, which would have blocked the star’s light in 2011, as noted by Kepler. Later, in 2013, the rest of the comet family, a band of varied fragments lagging behind, would have passed in front of the star and again blocked its light.
“By the time Spitzer observed the star in 2015, those comets would be farther away, having continued on their long journey around the star. They would not leave any infrared signatures that could be detected.”
Does that rule out the alien megastructures theory? NASA is not commenting on that angle, though it should be noted, as CNN did, that SETI has, thus far, not found any alien signals coming from KIC 8462852. Nevertheless, a NASA spokesperson said that further observations will be needed. In any case, scientists have all but concluded that the strange findings from KIC 8462852 were caused by nature and not aliens.
Even if comets are all there are orbiting KIC 8462852, such a finding will not rule out the existence of intelligent life somewhere else in the universe. Trillions of planets exist in our galaxy alone, and there are thought to be 100 billion galaxies in the universe. The chances that intelligent life did not evolve somewhere else would be, no pun intended, astronomical.