Earth is facing a "blind date" with a "serial killer" interstellar visitor which could "seed life" on our planet, a space boffin has warned. Theoretical physicist Avi Loeb says 3I/ATLAS has shown molecules of methanol and hydrogen cyanide, gasses which act as "precursors for the complex organic chemistry relevant to the origins of life."
And he says the mystery Manhattan-sized object - which is hurtling towards our planet at speeds of 130,000mph - could pose a threat to human life as hydrogen cyanide was used as a poisonous chemical weapon by France, the US and Italy during World War 1.
Loeb, a professor of science at top US university Harvard, said: "On a blind date with an interstellar visitor, it is prudent to observe the dating partner and decide whether it could have seeded life on Earth by carrying out interstellar panspermia or whether it represents a serial killer spreading poison."
But he conceded: "The anomalously large ratio of methanol to hydrogen-cyanide production by 3I/ATLAS suggests a friendly nature for this interstellar visitor."
Most of his peers think the 12-mile wide space rock is a harmless comet on a one-way journey through our solar system. But Loeb has repeatedly warned that world leaders should prepare for all eventualities in case of a life-changing alien close encounter.
In his latest blog post, he wrote: "Methanol is a building block for amino acids and sugars (like ribose, a component of RNA and DNA) which are fundamental to the organic chemistry of life-as-we-know-it.
"A diverse group of microorganisms including bacteria and yeasts, known as methylotrophs, are able to use methanol as their sole source of energy."
He added: "Hydrogen cyanide has been measured in Titan's atmosphere by four instruments on the Cassini space probe, one instrument on Voyager, and one instrument on Earth.
"Hydrogen cyanide is a poison at high concentrations but also an important signaling molecule at low concentrations in plants, animals, and microorganisms.
"The chemical properties of hydrogen cyanide allow it to serve as a precursor for the formation of complex organic molecules, such as amino acids and nucleic acid bases like adenine."
In November the professor said the "multi-jet structure" will arrive at its closest to Earth on December 19 in what could be our closest ever encounter with alien life and technology.