Out at about 6:00 tonight, I noticed an unusual cloud that I knew to be a rocket contrail (they’re occasionally visible from my my California hometown due to a nearby Air Force base). Rocket contrails in the evening sky reflect sunlight that the earthbound horizon has already rotated away from due to their great height; hence, their sharp contrast. The uneven pattern does not reflect the direct path of the rocket but rather windshear on the contrail. Such sights are only visible when a rocket is launched just prior to dawn or after dusk.
It was clearly south-north directed - i.e., from Tanegashima, where most Japanese launches are conducted, so I didn’t panic (if the direction had been reversed, I would have).
Unfortunately, I had no camera, but it looked a bit like this photo I snatched from the Web. Did any of our readers spot it and manage to capture an image? If so, please post it below. - William