What is going on with that atmosphere/light around the rocket in this photo?
What is going on with that atmosphere/light around the rocket in this photo?
This was a SpaceX Falcon 9 Block 5 launch from Cape Canaveral that occurred around 1900 local time on March 4th, 2024. The photo was taken from about 65km from the launch site. The rocket was in the 2nd stage.
Here's a video of the launch, but you can't really see the aura since the video is taken from the ship pointing at the rocket nozzle.
You are seeing the exhaust plume while it is still dense enough to reflect enough light from the sun.
There are several massive thermal layers in the atmosphere that effectively make isolation barriers at various heights. That is why the exhaust on the left appears unique in structure within a certain boundary. The upper layers of the atmosphere get really hot before getting really cold again. Like commercial jets fly in the cold part, but it gets hot, then cold above that. The rocket plume on the right is in that upper cold region; the outer most puffy/sparse/low Earth orbit region. You can tell because of how enormous the exhaust plume is expanding when there is very little atmospheric pressure to contain it.
There is very little atmosphere way up there and certainly not enough to produce Rayleigh scattering. If there was enough to produce Rayleigh scattering the exhaust plume would be hard to see with very little contrast against the background, but without, it makes a much higher contrast view against the mostly empty void of LEO space.
so what's the light reflecting off of?? ice? vapor? something else?
Exhaust products and a small amount of either O2 or unburnt. IIRC SpaceX is a fuel rich cycle, so mostly +unburned fuel.
Think of it kinda like you're seeing an isolated atmosphere made by the rocket suspended in a place nearly without atmosphere. It is like a cloud of atmosphere in space where there is no atmosphere.
It's mostly in the sun which is super hot without the filter of an atmosphere and how it buffers temperature. As soon is the particles are below the shadow of the Earth, they get super cold and likely freeze.
The rocket is clearly not at orbital velocity yet and that stuff is going backwards fast, so it will all deorbit fairly quickly.
You're not seeing turbulent flow quite like what happens on the ground or what is seen in other parts of the exhaust plume because there is not very much pressure in the surrounding region to create the Eddy currents that make the mixing/chaotic flow patterns seen within another medium. I don't think it is entirely linear flow, but it is much closer to linear flow than what happens in a thick atmosphere.
It's a space jellyfish!
No, really, that's the name for that phenomenon: https://en.wikipedia.org/wiki/Space_jellyfish