The sunspot measures a whopping 2700 microhemispheres (MH or millionths of a visible solar hemisphere). Now it has surpassed AR10486 (2610 MH) of the famous 2003 Halloween storms. It is the largest sunspot since AR6368, which measured 3080 MH on November 18, 1990.
AR12192 is the largest in almost 24 years!
A reminder for scale, the surface area of Earth is 169 MH.
Here is a look at the superspot from the Halloween storms (AR10486) and AR12192 using the SOHO/MDI and SDO/HMI instruments respectively.
Astronomer Lou Mayo of NASA Goddard Space Flight Center captured this image of the region despite the wind and clouds of Maryland.
Evolution of AR12192 seen with SDO/HMI, Oct. 15-23, 2014
Slightly zoomed-in view of the evolution of AR12192 seen with SDO/HMI, Oct. 15-23, 2014
credit: NASA/ESA/SOHO/SDO/L. Mayo