International Space Station and iridium pair at dawn, Alberta, Canada.

- Image ID: M7HECM
International Space Station and iridium pair at dawn, Alberta, Canada.
Stocktrek Images, Inc. / Alamy Stock Photo
Image ID: M7HECM
July 15, 2017 - The International Space Station in a dawn pass, as it flies away to the east after passing overhead. Blended in are images taken 20 minutes later of a pair of Iridium satellite flares in the dawn, the one below (Iridium 54) being the first to appear, at a predicted magnitude of -7, while the one above (Iridium 90) appeared one minute later at magnitude -3. Venus is the bright object at lower left in the dawn twilight above Aldebaran and below the Pleaides. Capella is at far left. The waning moon is overexposed at far right. This is a bit of cheat as the Iridiums were taken later than the ISS shots, but with the camera not moved and shooting a time-lapse through the entire sequence, from ISS appearance until the expected Iridium appearances later. The sky for the Iridiums was brighter and bluer than for the ISS set, so that had to be corrected for in brightness and selective colour adjustments. This is a useful image for comparing the ISS and Iridiums to Venus for brightness. However, by the time the ISS got into the east here, it had dimmed quite a bit from its peak in brightness overhead.
Location: Alberta, Canada