Astronomical Dictionary on Letter #F

Facula

Large, irregular, bright areas on the surface of the Sun, particularly near the limb. They precede t...

Filament

A strand of (relatively) cool gas suspended over the Sun (or star) by magnetic fields, which appears...

Fortuna

In Roman mythology, goddess of fortune, chance and luck....

feldspar

A group of rock-forming minerals that make up about 60% of the Earth's crust....

Fault

A fracture or zone of fractures in a planet's crust, accompanied by displacement of the opposing sid...