The first alien asteroid to visit our solar system might just be a dead rock drifting through space and not a sign of intelligent extraterrestrial life.

Breakthrough Listen, a group that looks for signs of that alien life throughout the universe, has not found any signals coming from asteroid ‘Oumuamua, which it locked onto after astronomers discovered it traveling relatively close to Earth and determined it had arrived here from outside the solar system.

The group was using radio telescopes to listen for alien signals in that range of the electromagnetic spectrum. “No such signals have been detected, although the analysis is not yet complete,” Breakthrough Listen reported on its website this week.

Out of the four ranges of radio signals the experts were observing, they have only finished analyzing information from one of them so far.

The group is also making data available on its archive for the public to comb through.

“It is great to see data pouring in from observations of this novel and interesting source,” Berkeley SETI Research Center Director Andrew Siemion said in the Breakthrough Listen update. “Our team is excited to see what additional observations and analyses will reveal.”

The alien hunters look for signals coming specifically from asteroid ‘Oumuamua by narrowing down input to signals that are drifting at the same rate as the real-life motion of the space rock. They also discard data that comes from human sources like satellite interference.

Astronomers from the European Southern Observatory announced last month that they had spotted ‘Oumuamua, whose path through the solar system suggests it is a foreign traveler — making it the first visiting asteroid to be discovered.

There are hundreds of thousands of known space rocks in the solar system, but all of them are believed to have a local origin. It’s possible that others which have yet to be identified are also immigrants to our solar system.

‘Oumuamua is unusually bright, suggesting it is elongated — its shape has been compared to that of a cigar. It is also dark red in color.

It’s still unclear what solar system the asteroid calls home.

“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. “However, even travelling at a breakneck speed of about [59,000 miles per hour], it took so long for the interstellar object to make the journey to our solar system that Vega was not near that position when the asteroid was there about 300,000 years ago. ‘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.”