Citizen skywatchers, amateur astronomers and scientists alike looked skyward today (May 9) to see Mercury pass across the face of the sun, an event that will not happen again until 2019.
The solar system’s smallest planet made a slow passage across the bright solar disc — an event that astronomers call a transit — starting at about 7:16 a.m. EDT (1116 GMT), according to NASA. The planet started on the left side of the sun’s disk and took a downward path to the right. Mercury finally exited the sun’s disk at about 2:38 p.m. EDT (1838 GMT). The event was visible from all of North and South America, Europe, Africa, and much of Asia.
From the perspective of Earth, Mercury completes a transit of the sun about 13 times per century. The last transit was in 2006, and the next one will occur in 2019. In addition to being a fascinating event for skywatchers, this somewhat rare celestial event offers a lot of information for scientists.