Tiangong-1, the first Chinese space station, is set to fall back to Earth around April 2. Its orbit had been slowly decaying since its service was ended in 2016. I found out that it would be visible for one last time in the sky this morning, so me and my daughter Celine decided to witness its streak. I set up my iPhone X on a tripod and placed it on the window facing north. Then I launched NightCap Camera app in satellite capturing mode.
Shortly after 5:30AM, Tiangong-1 made its bright (-0.6 magnitude, 181km altitude) appearance from the west, streaking towards east and quickly dimming. Just as it disappeared from our eyesight, another bright flash appeared to the east of Polaris and then quickly disappeared. From my experience I knew that was an Iridium flare. CalSky website verified it to be Iridium 80, showing up at 5:30:36AM with a magnitude of -2.0. We were very lucky to see the two together - since the space station will disappear in a couple of days it was truly a once-in-a-lifetime experience.
On the photo, you can see, starting from the top left and looking towards bottom right, the Tiangong-1, Polaris, Iridium 80, and the Cassiopeia constellation. Click on the image to see it in full size.
Device: iPhone X
Settings: 28mm - ISO 2112 - 61s - f/1.8
Date/Time: 2018-03-31 05:30:01 KST
Location: Naju, Korea