Sleek and mysterious, our solar system’s first interstellar visitor is being checked for alien technology

Astronomers are to use one of the world’s largest telescopes to check a mysterious object that is speeding through the solar system for signs of alien technology.

The Green Bank telescope in West Virginia will listen for radio signals being broadcast from a sleek cigar-shaped body which was first spotted in the solar system in October. The body arrived from interstellar space and reached a peak speed of 315,000km/h as it swept past the sun.

Scientists on the Breakthrough Listen project, which searches for evidence of alien civilisations, said the Green Bank telescope would monitor the object, named ‘Oumuamua, from Wednesday. The first phase of observations is expected to last 10 hours and will tune in to four different radio transmission bands.

“Most likely it is of natural origin, but because it is so peculiar, we would like to check if it has any sign of artificial origin, such as radio emissions,” said Avi Loeb, professor of astronomy at Harvard University and an adviser to the Breakthrough Listen project. “If we do detect a signal that appears artificial in origin, we’ll know immediately.”

The interstellar body, the first to be seen in the solar system, was initially spotted by researchers on the Pan-Starrs telescope, which the University of Hawaii uses to scan the heavens for killer asteroids. Named after the Hawaiian word for “messenger”, the body was picked up as it swept past Earth at 85 times the distance to the moon.

While many astronomers believe the object is an interstellar asteroid, its elongated shape is unlike anything seen in the asteroid belt in our own solar system. Early observations of ‘Oumuamua show that it is about 400m long but only one tenth as wide. “It’s curious that the first object we see from outside the solar system looks like that,” said Loeb.

The body is now about twice as far from Earth as the sun, but from that distance the Green Bank telescope can still detect transmissions as weak as those produced by a mobile phone. Loeb said that while he did not expect Green Bank to detect an alien transmission, it was worth checking.