Meaning: “A messenger that reaches out from the distant past” (in Hawaiian).
Appearance: Dark, reddish, about 400 metres long by 40 metres wide, so roughly the size and shape of a skyscraper.
Age: Maybe a few hundred million years?
You don’t know, do you? No. But ‘Oumuamua is generally mysterious. It was spotted last October whizzing past the sun, too fast to have originated in our solar system. It was declared the first interstellar object ever discovered, before disappearing from view in January.
Cool. It was long and thin, unlike any asteroid or comet seen before. And its surface was carbon-based, not ice or rock. And – get this – after passing the sun, it suddenly sped up. So now some scientists are speculating …
Aliens! Perhaps. In a new paper in the Astrophysical Journal Letters, the Harvard professors Shmuel Bialy and Abraham Loeb discuss a range of theories to explain ‘Oumuamua’s strange behaviour. I don’t want a range of theories. I want aliens. Settle down. Initially, the acceleration was put down to outgassing.
(Snigger.) When comets pass close to stars, they release gas that can speed them up. No gas was detected from ‘Oumuamua, but it might have been released quite gently.
Silent but violent. Indeed. However, Bialy and Loeb say it could also have been pushed by the sunlight striking it, like a deliberately designed solar sail.
That’s right. Designed by aliens. Of course, it was scanned last year for radio signals, and wasn’t sending any. They probably use subspace transmission, like on Star Trek. ‘Oumuamua was also tumbling wildly around. How else would you generate artificial gravity? Nor is it clear why aliens would send a probe that would take millions of years to reach us.
They’re aliens. They live to probe. “One possibility,” the authors suggested, “is that ‘Oumuamua is a light sail, floating in interstellar space as debris from an advanced technological equipment.”
So it’s a piece of broken spaceship? Well … we can’t prove it’s not. Although it is much more likely to be an asteroid, or a comet covered with an irradiated crust. The alien theory really doesn’t have much evidence.
Boo, evidence! I want fun lies. Of course, if it’s an asteroid it might be a splinter of another planet destroyed by an exploding star. All right. I suppose that’s quite fun, too. Unless there were aliens on the planet. Do say: “Typical! You finally find an alien probe and the damn thing’s broken.” Don’t say: “We come in pieces.”