Largest solar granules

Convection currents within the Sun cause a phenomenon known as granulation on the photosphere. Each granule is formed as hot hydrogen rises in its centre and then falls again around its edge. A typical granule is around 1,000 km across and can last for less than 20 minutes. First discovered in the 1950s, supergranules measure around 30,000 km across and represent larger-scale currents in the Sun, which has several thousand of these features at any time.