Planet Mercury transiting in front of the sun


Mercury is the closest planet to the Sun. Seen from the Earth, it therefore does not move far from it and occasionally passes squarely in front of the surface of the Sun. Their size difference is enormous. Mercury is only 4,900 km in diameter while the Sun is more like 1.4 million km, 284 times wider.

On May 9, 2016, Mercury passed in front of the Sun and the size difference is clearly visible. In this photo, which I was able to take using a specialized filter, we only see part of the Sun’s disk. Mercury is profiled in black because we can see its side not illuminated by the Sun.

Technical details:

Telescope: Celestron Edge HD14  (focal length: 3,910 mm)
Mount: Paramount MX+
Camera: ZWO ASI 174 MC
Filter in front of the objective lens: Baader Astrosolar 3.8
Filter in front of the sensor: 1.8 neutral density
Exposure: video capture with FireCapture and only 1 image slected and processed
Place: Backyard observatory in Sainte-Sophie, Qc
Date: May 9, 2016