Figure 9-12Helioseismology (a) This computer-generated image shows one of the myriad ways in which the Sun vibrates because of sound waves resonating in its interior. The regions that are moving outward are blue; those moving inward are red. The cutaway shows how deep these oscillations are believed to extend. (b) This cutaway picture of the Sun shows how the rate of solar rotation varies with depth and latitude. Red and yellow denote faster-than-average motion; blue regions move more slowly than average. The pattern of differential surface rotation, which varies from 25 days at the equator to 35 days near the poles, persists at least 19,000 km (11,800 mi) down into the Sun’s convective layer. Sunspots preferentially occur on the boundaries between different rotating regions. Earthlike jet streams and other wind patterns have also been discovered in the Sun’s atmosphere.