On 9 May 2016, Mercury passed directly between the Sun and Earth. This event, which is called a transit, happens about 13 times each century.
NASA’s Solar Dynamics Observatory, or SDO, is a satellite in an inclined geosynchronous orbit about the Earth that studies the Sun 24/7 and captured the entire seven-and-a-half-hour event.
This composite image of Mercury’s journey across the Sun above was created with visible-light images from the Helioseismic and Magnetic Imager on SDO.
While watching the following time-lapse video, bear in mind that Mercury is the smallest planet in the solar system with a diameter of 3030 miles (4880 kilometres), just 38 percent the size of the Earth.
The Sun has a diameter of 864,600 miles (1,391,400 kilometres) — in excess of 285 times the diameter of Mercury.