We'd always assumed interstellar objects were out there; we'd just never caught one passing through. Then 'Oumuamua appeared, behaved like neither asteroid nor comet, and left before anyone could get a proper look. The fight over what it was — a hydrogen iceberg, a shard of a shredded planet, or a discarded piece of alien machinery — is really a fight about how strange we're willing to let the universe be.
Discovered October 19, 2017 by Pan-STARRS: a hyperbolic orbit proving it came from outside the solar system, a tumbling cigar-or-pancake shape, and the anomalies that launched a thousand arguments.
Karen Meech tells the story every stargazer dreams of: the frantic days her team spent chasing a fast-fading dot across the sky before it slipped away from us forever.
PBS Space Time on what the data actually showed — the violent tumble, the extreme elongation, and the detective work tracing where in the galaxy this thing might have been flung from.
Harvard's Avi Loeb and Shmuel Bialy argue 'Oumuamua's unexplained acceleration fits a thin, sunlight-pushed sail — possibly a piece of technology built by another civilization.
Over three hours with Lex Fridman, Loeb explains why he refuses to rule out technology, and why he thinks science has grown too timid to even look for it.
The rebuttal. Space Time walks through the natural explanations one by one — and why 'it's never aliens... until it is' still lands, this time, on 'not aliens.'
Outgassing from an exotic, nearly tail-less comet — or a fragment torn from a shattered world — can explain the strange acceleration without invoking any engineers at all.
Anton Petrov lays out the leading natural model — a 'hydrogen iceberg' or nitrogen shard quietly evaporating in sunlight — and what the next interstellar visitor could finally settle.