In 2017, astronomers discovered a space rock that hailed from another star system. The interstellar object, which was subsequently named 'Oumuamua, has since then intrigued scientists.

Alien Spacecraft

Some think that the cigar-shaped object could be an alien spacecraft. In a newly released study published in The Astrophysical Journal Letters, for instance, astrophysicists from Harvard proposed that the 'Oumuamua could be a debris from a now-defunct craft tumbling through space, or a reconnaissance probe launched from elsewhere in the galaxy.

The idea that the supposed interstellar asteroid is an alien spacecraft has prompted scientists at the SETI (Search for Extraterrestrial Intelligence) Institute in Mountain View, California to use the Allen Telescope Array to observe the object when it was about 170 million miles away.

Signals To Prove Artificial Origin Of 'Oumuamua

SETI scientist Gerry Harp and colleagues wanted to measure artificial radio transmission from the object, which, if found, could serve as strong evidence that the 'Oumuamua is not just a rock tossed into space by a natural phenomenon that occurred in its home star system.

The researchers looked for signals that could prove the object incorporates some technology.

They listened for pings with a frequency ranging from 1 to 10 gigahertz, with a resolution of 100 kilohertz. The observation campaign can pick up signals produced by an omnidirectional transmitter with a power between 30 and 300 milliwatts.

The search, however, came up empty.

No Artificial Signal Detected

"We were looking for a signal that would prove that this object incorporates some technology - that it was of artificial origin," Harp said. "We didn't find any such emissions, despite a quite sensitive search. While our observations don't conclusively rule out a non-natural origin for 'Oumuamua, they constitute important data in accessing its likely makeup."

The findings will be reported in a paper to be published in the February 2019 issue of Acta Astronautica.

This isn't the first time that scientists attempted to eavesdrop on 'Oumuamua. The $100 million Breakthrough Listen project also made an attempt using the Robert C. Byrd Green Bank Telescope in West Virginia, and the result also turned up nothing.