ORLANDO, Fla. – Night launches are great in and of themselves, but every now and then launches just before sunrise provide an extra treat for spectators. If you were up early Saturday to see SpaceX launch another round of Starlink satellites you may have seen the brilliant display in the sky shortly after.
The clouds are created like the contrails you see leftover from jet aircraft as they fly through cold, dry air aloft. In this case, the trail of exhaust left by burning rocket fuel passed through an area of cold, dry air and quickly froze in the conditions. The sun was still below the horizon for the 5:21 a.m. launch, but as the Falcon 9 rocket got higher in the sky, the sun’s rays were able to reflect off the frozen exhaust.
The sun reflecting off of the ice crystals illuminated the cloud above while the surface was still in darkness.