Breakthrough Listen, a £74 million search for intelligent alien life, is using the world's largest manoeuvrable radio telescope at Green Bank in West Virginia to track the object. "'Oumuamua may well have been wandering through the Milky Way, unattached to any star system, for hundreds of millions of years before its chance encounter with the solar system".
It's still unclear what solar system the asteroid calls home.
They are listening for electromagnetic signals, no stronger than those emitted by a mobile phone, that can not be produced by natural celestial bodies.
"It is great to see data pouring in from observations of this novel and interesting source", Andrew Siemion, director of the Berkeley Search for Extraterrestrial Intelligence Research Center in California, said in a statement.
'They all turn out to be natural, until one doesn't.
Oumuamua is a Hawaiian term meaning "a messenger from afar arriving first".
So far, there has been no evidence of artificial signals emanating from the object, but sorting through the large volumes of data collected may take some time to complete. Listen observed 'Oumuamua across four radio bands (corresponding to four of the radio receivers available at Green Bank, denoted L, S, X, and C), spanning billions of individual channels across the 1 to 12 GHz range.
In addition to calibration observations, the instrument accumulated 90 TB of raw data over a 2 hour observation of 'Oumuamua itself.
"'The more I study this object, the more unusual it appears, making me wonder whether it might be an artificially made probe which was sent by an alien civilisation, ' Professor Avi Loeb, the chair of Harvard's astronomy department and one of Milner's advisers on Breakthrough Listen, wrote in the email". Its shape also has experts at Breakthrough intrigued. Astronomers predict that Oumuamua will leave our solar system in January 2019. Earth-based telescopic observations of 'Oumuamua after it was discovered on October 19, 2017 by the University of Hawaii's Pan-STARRS 1 telescope on Haleakala indicated that the object was on an open-ended hyperbolic course that had already brought it to within 0.25 AU (23 million mi, 37 million km) of the Sun in September, and that it was speeding back into deep space at 95,000 km/h (59,000 mph).
It is the first known object from another solar system to pass close to Earth.
Asteroids are small, rocky objects that orbit the Sun.
Analysts also say its faintly red colour indicates it has been subjected to interstellar cosmic radiation which is harsher than we experience in our solar system.
"Preliminary orbital calculations suggested that the object had come from the approximate direction of the bright star Vega, in the northern constellation of Lyra", the ESO said last month.
Earlier this year, astronomers discovered what they think could be the first-ever-observed interstellar object.