SPOTS ON THE SUN.

Thames Star, Volume LVII, Issue 14727, 4 August 1921, Page 8

SPOTS ON THE SUN.

The largest spots on the sun, usually show themselves in February or August, but science has not yet discovered why this is so. Among other mysteries connected with sunspots is their appearance in' larger numbers than, usual every eleven years or so. ' When they are seen most abundantly the period is known as 'the "maximum spot cycle," and when the sun is almost clear of them the period l is called the "minimum spot cycle." Both periods occur at regular intervals. These spots' are caused by whirling masses of gas on the sun's interior with an appalling speed and appears dark only in comparison with the sun's brilliant outer Perhaps the largest spot ever photographed at Greenwich Observatory was that of February 4th, 1i909, which covered an area of nearly 4,000 million square miles.. Another group of spots is said to have had an area of 3780 million square miles. Such giant spots are distinctly visible with the naked eye. The earth in one of them ..would be like a pea in a pint pot.