Interstellar object ­Oumuamua is debris not aliens, Australian astronomers believe

SECRETS of a mysterious cigar-shaped object that ­entered our solar system last year — prompting speculation it may be an alien spacecraft — have been uncovered by ­astronomers in the Outback.

SECRETS of a mysterious cigar-shaped object that ­entered our solar system last year — prompting speculation it may be an alien spacecraft — have been uncovered by ­astronomers in the Outback.

The mass, named ­Oumuamua, was discovered last October and is the first rec­orded interstellar object to pass through our solar system.

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“If advanced civilisations do exist elsewhere in our galaxy, we can speculate that they might develop the capability to launch spacecraft over interstellar distances and that these spacecraft may use radio waves to communicate,” said Curtin University’s Professor Steven Tingay.

An artist impression of the first interstellar asteroid: Oumuamua. Picture: AFP Photo.

“Whilst the possibility of this is extremely low, possibly even zero, as scientists, it’s ­important that we avoid ­complacency and examine observations and evidence without bias.”

The Murchison Widefield Array telescope in remote Western Australia has been used to “listen” to Oumuamua, which is between 95 million and 590 million kilometres from Earth, and identify any signs of radio frequency ­transmission.

Prof Tingay assessed frequencies of 72 and 102 MHz — similar to the range in which FM radio is broadcast — but no activity was identified.

Separate work by optical telescopes indicated ­Oumu­amua — Hawaiian for “a messenger that reaches out from the distant past” — is most likely the remains of a huge comet or asteroid bombarded by cosmic rays on its journey across space.

Given the object’s strange orbit, the first to be detected as originating in another solar system and crossing into our Milky Way, and its distinctive shape — about 200m long and 35m in diameter — some scientists believed it may have been an alien body or vehicle.

“We couldn’t rule out the possibility it was a spacecraft from another civilisation, although it was an extremely low probability,” Prof Tingay said.

But its silence and the optical observations have concluded it is likely to be a cometary fragment “on a journey for maybe hundreds of millions of years”.

And as for signs of alien life, Prof Tingay said: “We will keep looking.”