if the comet is streaking through the galaxy... then what is the green stuff IN FRONT of it? wouldn’t the mass of the comet be in the body and moving the fastest? is there some form of gas or some other substance being pushed out ahead of the body of the comet that is diffusing the light?
I know....That is why I thought *Wormwood*
You're used to how things work with atmospheric drag. Since there is no atmosphere in space the results of the ice in the comet sublimating tends to hang around the comet until the solar wind pushes it away from the sun. Anything on the sun's side of the comet will initially move forward of the comet.
When the comet is traveling away from the sun, the tail leads the comet on the way away from the sun. When it is closet to the sun, the tail generally perpendicular to the travel path.
A comet can have two tails.
One is made up of neutral dust particles and water vapor. Those get pushed around by the solar wind and while initially streaming out behind it (along the path it has travelled) it will end up pointing away from the sun, even if that’s 90 degrees away from where the comet is going.
The other is made up of ions and other electrically charged particles. Those follow the solar magnetic field. That can be a different direction. Post #16 in this thread shows an example.