Great. The Collectors are here.

http://masseffect.wikia.com/wiki/Collector_Cruiser

They said they believe it is interstellar because of its improbable orbit. This is a classic example of the assumptions that undergird much of modern cosmology

Uh, what? Nobody said that at all. It is neither a "classic example" nor an assumption. The trajectory has been tracked since it was discovered, which is hyperbolic around the sun, and the speed of the object is such that there is no way it could have accelerated to its current velocity due to the gravity of our sun alone, hence it has to be interstellar, picking up kinetic energy from another system outside of our own. The orbit is not improbable, it is unusual compared to trajectories of asteroids that exist within our own solar system. Sharpen your crayon there bud, and stop trying to impress people with your new thesaurus for hipsters (come on, "undergird"?? Really?)

Assumption = a thing that is accepted as true without proof
Inference = a conclusion reached on the basis of evidence and reasoning
Undergird = provide support or a firm basis for

"This is a classic example of a conclusion reached on the basis of evidence and reasoning that provide support or a firm basis for much of modern cosmology". There, I fixed it for you.

LOL. Do you have a counter-hypothesis?

Comment hidden because you are ignoring dag.(show it anyway)

Arthur C. Clarke's predictions in his SF have been eerily prophetic. I would love it to be Rama.

But it's probably not ... :-(

Sift of the week anyway.