Partial Solar Eclipse, May 20, 2012 The moon will block 53% of the sun. The sun sets only 45 minutes after the eclipse begins. The path of annularity will begin in southern China and move east through Japan, the northern Pacific Ocean, and into the western United States. Plan to observe from a location with a good western horizon so you can observe the sun setting while it is still 53% eclipsed. Starts 7:25pm; Alt=7.5 deg, Az=296 deg Sunset 8:05pm