Abstract: Observations of Jupiter’s Great Red Spot (GRS) span more than 150 years. This allows for careful measurements of its size and drift rate. High spatial resolution spacecraft data also allow tracking of its spectral characteristics and internal dynamics and structure. The GRS continues to shrink in longitudinal length at an approximately linear rate of 0 deg .194 yr(exp -1) and in latitudinal width at 0 deg .048 yr (exp -1). Its westward drift rate (relative to System III W. longitude) has incr…