Granules are regions of the Sun where hot solar material comes to the solar surface. Granules are about 600 miles (1,000 km) across and only exist for about 5 to 10 minutes before they fade away. It is almost as though the surface of the Sun is bubbling like a pot of boiling water.
on the solar photosphere about two and one half million granules exist at any moment. The average granule is 1000 kilometres across; it survives from five to ten minutes. Granules are about 100 K hotter than their surroundings. They show a turbulent motion of about 2 kilometres per second, like a bubble in a porridge pot (Abell, p. 526).
A variable region of rising or sinking mass on the solar photosphere, thus giving the Sun a mottled appearance.