Mars rover discovers mysterious 'blueberries'

[sofa king]

29. I have two guesses:

1) They are "iron rain," droplets of molten iron and silicon ejected from an enormous impact by an iron-rich asteroid. The droplets solidified after minutes or hours of falling back to the surface;

2) They are ooids, not quite like the CaCO2 ooids that form around shell fragments in our oceans, but formed in a similar way, which suggests large bodies of open water and regular wave action.

I should add that I have barely any idea what I'm talking about, but I cannot help guessing anyway.