We watched the Wallops Island launch from from the beach in southern NJ. It was pretty cool. I didn’t expect to see much more than a speck of light but the plume was plainly visible. It reminded me of a memory from my childhood that I am not sure is accurate.
I seem to recall a launch (or two?) of something in the late 60s. The result was a yellow/orange “cloud” (like something went up and exploded) in the SE night sky as viewed from the Philadelphia area. This would be consistent with a Wallops Is. launch if they were even doing that sort of thing there at the time. Our neighbor was a science teacher and I thought she gave us an explanation but I’ll be damned if I can remember what it was. However, to paraphrase Archie Bunker - the whole thing might be just a fig in my imagination. Any ideas?
Do a Google image search for [high altitude rocket plume] and look at the pretty pix. There are several where you see a trail that blossoms outwards. Watching as those are created looks a lot like a slo-mo explosion.
What you’re seeing is a staging. At the right time of day they can be very spectacular when the rocket is way up in the sunlight and it’s before dawn (east coast) or after dusk (west coast) down on the ground.
The other thing that happens is the winds at very high altitude can be pretty chaotic. So what starts out as a mostly straight line gets coiled into a spaghetti-like mess.
As well, your perspective on the trail is not what you think it is. Even though Wallops is some distance away, you’re mostly looking right up the ass-end of the trail. IOW: it began 40 miles away from you horizontally, but at the far end it’s 30 miles up and 500 miles downrange to the east. At that 500 mile distance the few miles of lateral and vertical offset is negligible; you’re mostly looking at the trail end-on from near the origin.
I think beowulff got it. The neighbor said something about chemicals being released, if my memory serves me correctly. On the Antares launch, at least, the plume (actually the pretty narrow, long, pointy flame) was easy to see early on but once it got to 45-60 degrees or so above the horizon it became the end-on dot like LSL says. No cloud-like plume though. I knew rockets don’t actually launch straight up but had never seen one before and was mildly surprised at the angle. Maybe the sun was too far below the horizon to light the plume up. Thanks guys.