SolarHam.com | Sunspots 1504, 1505 and 1507 - SDO / HMI (6/12/2012)

Sunspot 1504 continues to expand into a large sized sunspot cluster and now spans the size of at least 4 planet Earths. This movie by SDO / HMI shows the formation of Sunspots 1504, 1505 and 1507 over the last several days.