Overview of the large impact, impact 12, as seen in UV (1600 Å) and EUV (171, 193 and 211 Å) channels. The EUV images are base differences with a base image at 07:50:00 UT. The red/blue contours outline magnetic fields of +/−50 G. The white arrow in (f) points to bright EUV emission produced by a low density impact. The black arrow in (m) points to diffuse 1600 Å emission during the second stream of impacts.