Transit of the Sun by the International Space Station and Cicadas

August 27, 2021



Photographer: Wayne Robinson 
Summary Author: Wayne Robinson 

The photo above shows a 5-second composite of a transit of the International Space Station (ISS) passing over the Sun as observed from my location in Bowie, Maryland. About 8 minutes before I activated the shutter, among the trillions and trillions of photons emitted by the Sun (about 1.5x10^43 photons), a very select number - about 4.5 tera photons (4.5x10^12) - made it to my camera's detector. At the time, the Sun's disk was uniformly bright except for a sunspot about half-way out from the center -- at the 6:30 position. This spot, as with all sunspots, is dark due to a relative cooling of the Sun's surface caused by a local disturbance in its magnetic field.

The ISS took only about 3.4 seconds to cross the solar disk. Note that at this time it was approximately 870 miles (1,400 km) from the camera. Just one second before the ISS transit occurred, a pair of winged creatures, likely periodical cicadas from Brood X, flew past the solar disk, taking perhaps ½ second to do so, giving the Sun's face on this exposure a number of curious "eyes." Photo taken June 8, 2021, at 7:30 p.m. (local time).

Photo details: Canon 80D camera; Canon 400 mm telephoto lens; 2 x and 1.4 x teleconverter.

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