Possible ‘Alien Mega Structure’ May Be Communicating, But Not With Earth, Claims SETI
Several telescopes are already pointed at the star in question. But what was captured?
If there are a̳l̳i̳e̳n̳ c̳i̳v̳i̳l̳i̳z̳a̳t̳i̳o̳n̳s̳ transmitting data around a distant star, the signals are too weak for us to detect here on Earth.
The star KIC 8462852 came to the world\’s attention in October 2015 when scientists announced evidence of periodic dimming of 20% or more, which some people theorized was caused by the shadow of an a̳l̳i̳e̳n̳ megastructure. However, observations of KIC 8462852 by researchers at SETI (Search for Extraterrestrial Intelligence) in California have so far failed to capture radio signals that could indicate some sort of a̳l̳i̳e̳n̳ transmission.
Allen Telescope Array (ATA) used to detect possible signs of a hypothetical c̳i̳v̳i̳l̳i̳z̳a̳t̳i̳o̳n̳
advanced e̳x̳t̳r̳a̳t̳e̳r̳r̳e̳s̳t̳r̳i̳a̳l̳ around the star KIC 8462852.
Credits: Seth Shostak / SETI
“The history of astronomy shows us that every time we thought we had found a phenomenon linked to e̳x̳t̳r̳a̳t̳e̳r̳r̳e̳s̳t̳r̳i̳a̳l̳ activities, we were wrong”, comments astronomer Seth Shostak of the SETI institute. “But while it is very likely that this is just a strange and natural behavior of the star, it is wise to check the facts to be sure.”
“No clear evidence”
The Kepler Space Telescope has a mission to find planets around distant stars, through the brightness dips of the stars when their planets pass in front of it. Observations made on the star KIC 8462852 showed that it was dimming in a very peculiar way, and extremely unlike anything we\’ve seen before. Because of this strange dimming, some astronomers deduced that it could be some gigantic structure passing in front of the star during our observations.
In addition, several natural explanations have been proposed, including the presence of a swarm of comets orbiting the star. KIC 8462852 is located 1,480 light-years from Earth in the constellation Cygnus (Swan), between the stars Deneb and Rukh, close to the star cluster NGC 6866, as shown in the image below:
Location of the star KIC 8462852 in the constellation Swan, close to the star cluster NGC 6866
Credits: Wikimedia Commons / Roberto Mura
But considering all the possibilities, the one that captivated the attention of the general public was the idea that the star studied by Kepler could host a̳l̳i̳e̳n̳ mega-structures in orbit, which would be built by technologically advanced c̳i̳v̳i̳l̳i̳z̳a̳t̳i̳o̳n̳s̳.
With this possibility in mind, the SETI Institute pointed the Allen Telescope Array (ATA) at the star in question, observing it for more than two weeks.
The ATA telescope examined the star in two different types of signals:
Narrowband – make up the majority of SETI surveys, and are considered plausible for advanced societies to use a “greeting sign” in the event of the presence of other c̳i̳v̳i̳l̳i̳z̳a̳t̳i̳o̳n̳s̳;
Broadband – could come from a̳l̳i̳e̳n̳ spacecraft undergoing maintenance or any other project around the star, and there could be intense microwave beams leaking into the spacecraft.
“This is the first time I\’ve used the Allen Telescope Array to look for broadband signals, a type of emission that is generally not considered in SETI surveys,” said Gerry Harp, a scientist at the SETI institute.
But despite great efforts, SETI announced in a November 5th statement that there was no clear evidence of any signs of e̳x̳t̳r̳a̳t̳e̳r̳r̳e̳s̳t̳r̳i̳a̳l̳ c̳i̳v̳i̳l̳i̳z̳a̳t̳i̳o̳n̳s̳. The research excludes omnidirectional transmitters that use a minimal amount of energy to transmit their signal. That minimum is about 100 times the total amount of energy currently used on Earth (landside) for narrowband signals, and 10 million times greater than for broadband emissions, the researchers said.
The results do not rule out the possibility that a̳l̳i̳e̳n̳ communications are taking place around the star, but rather that, if they exist, they are too weak to be picked up here on Earth using the technology we use. The main limitation would be the large distance between Earth and the star, about 1,480 light-years, the scientists said.
However, the researchers note that if any e̳x̳t̳r̳a̳t̳e̳r̳r̳e̳s̳t̳r̳i̳a̳l̳ c̳i̳v̳i̳l̳i̳z̳a̳t̳i̳o̳n̳s̳ around the star KIC 8462852 were deliberately sending signals in the direction of our Solar System, they would know how much energy would be needed to be captured here on Earth. The researchers note that any society capable of building such advanced technology should have the ability to utilize a strong enough intensity, hundreds of billions of watts.
Observations of the star will continue, not only by the SETI institute, but also by several other ground-based telescopes, and in the future, by space telescopes as well. But the researchers caution: if any advanced a̳l̳i̳e̳n̳ c̳i̳v̳i̳l̳i̳z̳a̳t̳i̳o̳n̳s̳ are out there, around this star, their inhabitants don\’t appear to be communicating directly with Earth.