This post from March is timely now — also, there’s an update, with a movie of the asteroid. Update, April 24, 2020: Here’s the visitor:
That’s salt — we couldn’t live without it. Salt is a mineral. It’s really difficult to mention “minerals” without your listener’s eyes glazing up and
No, not moss, lichen, and grass. Plate tectonics! That split in the ground of Iceland shown above is where two tectonic plates are spreading apart.