Unfortunately I sometimes remember things in an untidy manner, like iron filings 2-4cm long clinging to the sample-arm magnets of the Viking landers.

Where did that little bit of mostly irrelevant knowledge come from? Heck if I know now! It was probably 25 years ago anyway, and one loses track.....;-)

Don't remember anyone claiming they were chains of tiny iron oxide particles attracted to the strong magnets on the landers, and thus -- like so much on Mars that mimics something else -- initially looked like long, intact iron filings, but maybe somebody did.

Thanks for filling in those gaps.

What could cause long iron filings to be common on Mars? If that's what the Vikings were picking up, it would be a pretty astonishing finding. Unprecedented. Unimaginable. Inconceivable!

Unless... something was happening on Mars that effectively "sprayed" iron fragments into the atmosphere. An impact of an iron-rich asteroid perhaps? Or contrariwise, an iron-rich eruption?

But assuming such long iron fragments could be produced at all (and I'm not sure either mechanism could actually do it), how would they persist over the ages on such a highly "rusted" Martian surface? By rights, if they were ever there at all, they should have rusted away to dust very quickly.

I guess it'll just have to be a mystery....



Cheers, BFelix