Scientists have searched one of the only known visitors to us from another solar system for signs of alien technology – and found nothing.
3I/ATLAS was discovered last year and identified as the third such interstellar visitor ever found, after 1I/’Oumuamua and 2I/Borisov. The rare and unknown nature of such objects has led to speculation that they could even be spacecraft sent by alien civilisations.
Now, the SETI Institute – set up to look for signs of extraterrestrials – says that it has scanned the object and found that it appears to be a natural object after all. But researchers say that the finding is useful, and could help us better understand what we might see if we do really examine an object that was made by alien life.
“Eventually, our own Voyager spacecraft will be extraterrestrial artifacts in other stellar systems,” said Sofia Sheikh, lead author on the new paper. “Given that, it is important that we understand the natural distribution of interstellar objects so that we will be able to identify any anomalies that could one day be signs of an artificial interstellar object.”
The researchers examined 3I/ATLAS for eight hours, using the Allen Telescope Array in California. They looked at it across a range of different frequencies of radio signals, examining specifically those that are not produced in nature.
They found 74 million narrowband signals, of the kind that are thought to be produced only by artificial technology. But after removing human interference and tracking the ones that followed the movement of the interstellar object, only 200 remained and those were found to be coming either from Earth or own satellites.
Researchers say that the findings show that we could be ready to find such signals if they are out there, as well as demonstrating how quickly and successfully our equipment can scan for them when an interesting object is spotted.
“The results from 3I/ATLAS show how realistic it is to detect a signal with the technology we have today,” said Valeria Garcia Lopez, co-author. “That is why it is important to keep searching for technosignatures, even from objects we might not expect to have signals.”
The work is reported in a new paper, ‘A Search for Radio Technosignatures from Interstellar Object 3I/ATLAS with the Allen Telescope Array’, published in The Astronomical Journal.
