This sequence of Mercury's rare transit across the sun was shot every ten minutes on November 8, 2006.   The planet's silhouette can be seen moving from left (11:11 a.m. PST) to right (1:41 p.m. PST) in front of the sun's brilliant photosphere.  Sunspot 923, which is just rounding the sun's limb on the left, is many times larger than the Earth.  The next transit occurs when Venus crosses the sun in 2012.