Find entries starting with containing

facula
A circular to subcircular region which is brighter than the surrounding area.

filament
A strand of cool gas suspended over the photosphere by magnetic fields, which appears dark as seen against the disk of the Sun; a filament on the limb of the Sun seen in emission against the dark sky is called a prominence.

fireball
A bright meteor.

fissure
a narrow opening or crack of considerable length and depth.

fluctus
Flow terrain.

fossa
A long, narrow, shallow depression.

fracture
A break or crack.

friction
The rubbing of one surface or thing again another.