[X] My Assistant

[Holder of the Tw...]

They finally found a chunk of something coming into the Solar System. Something much bigger than cosmic rays or dust particles.

Asteroid/comet in hyperbolic trajectory

[TheAnt]

So we have to accept that 1I/2017 U1 truly have one remarkable shape.
According to one hypothesis it could have been formed from metal during the early phase of a stellar system in making, when the cores of small asteroids were molten.
In that case it had been 'squirted' out as two minor blocs collided.

The other one already proposed here is that it's a shard, it does not necessarily need to be caused by a collision.
Temperature swings can have rocks crack also, and so it might have left the parent body in a less dramatic way.

But I got one of my own, based on nothing else but garage physics and my experience of sandblasting.
That is that it started out as an oval object, since then have been eroded by micrometeorites and so have gotten the current shape.

And yes I agree, Arthur C. Clarke would have been amused to write an essay on this one.

[dudley]

So we have to accept that 1I/2017 U1 truly have one remarkable shape.
According to one hypothesis it could have been formed from metal during the early phase of a stellar system in making, when the cores of small asteroids were molten.
In that case it had been 'squirted' out as two minor blocs collided.

The other one already proposed here is that it's a shard, it does not necessarily need to be caused by a collision.
Temperature swings can have rocks crack also, and so it might have left the parent body in a less dramatic way.

But I got one of my own, based on nothing else but garage physics and my experience of sandblasting.
That is that it started out as an oval object, since then have been eroded by micrometeorites and so have gotten the current shape.

And yes I agree, Arthur C. Clarke would have been amused to write an essay on this one.

A 'squirting out' of molten material, which forms, essentially, a cylinder, strikes me as surprisingly organized. A multitude of roundish blobs seems likelier.

If Oumuamua is a shard, one wonders why we don't see its like in asteroids belonging to our solar system. Granted, a long history of collisions would probably break up a long thin asteroid into smaller pieces. But wouldn't more recent collisions make ones that we could still observe?

Long shards recently cracked off larger asteroids in our solar system by cycles of heat and cold should still be observable, too, shouldn't they? The closest we have seems to be Eros, but it's only about 3 times longer than it is wide; more of a 'potato' than a 'thin cigar'.

Fine particles in space could erode an asteroid, but would probably do so evenly across its surface. Its rotation should facilitate that, as would the multidirectional distribution of the particles.