Sunspot Up Close. The Suns complex magnetic field creates this cool region by inhibiting hot material from entering the spot. Sunspots can be larger than the Earth and typically last for only a few days. This high-resolution picture also shows clearly that the Suns face is a bubbling sea of separate cells of hot gas. These cells are known as granules. A solar granule is about 1000 kilometres across and lasts about 10 minutes. After that, many granules end up exploding.