Posts tagged ‘mercury d800’
Today Mercury slid over the sun and I shot it with an additional infrared 850 nm filter. Mercury is at the bottom, a sunspot is visible on the Sun upper hemisphere.
A 70-200 VRII mounted on the 36 Mpx D800 gave a resolution of 2 pixels for Mercury passing over the Sun and 370 pixel for the Sun. Knowing the Sun is 1.64 times more distant than Mercury from Earth, the size ratio Sun / Mercury is 370*1.64/2 = 303.4 . Known the Sun diameter is 1.3914 million km, Mercury measures 4,586 km in diameter (the real value is 4,800 km).
The same camera setting gives a resolution of 12 pixels for Jupiter, which is 6.8 times more distant from Earth than Mercury. Therefore the size ratio Jupiter / Mercury is 12*6.8/2 = 40.8 . Calculated that Mercury is 4586 km in diameter, Jupiter is 187,108 km (its real size is 143,000 km). More or less …