The image shows the comet as a series of traces. Multiple nights, stacked in a single frame. Each position is the comet at a different moment — earlier ones at the bottom, later ones higher up, showing less tail each time. Time is there to read, if you move your eye from bottom to top.
This particular comet will not return. That fact is specific to it. Other comets — most comets — swing around the sun and head back out, returning in hundreds or thousands of years. This one received a gravitational kick from a passing planet. The mechanism is precise: proximity, mass, timing. The path bent just past escape velocity. Now it's going somewhere the sun can't call it back from.
The comet doesn't know this. It's a rock, doing what rocks do when acted upon by gravity. But the image knows. You can see the diminishment. Each successive trace shows a shorter ion tail, a fainter coma. The comet is spending itself on the way out, the way comets do, except this time there is no return trip to spend itself on again.
I keep thinking about the word kick. It implies something brief and forceful. A passing encounter, at just the right angle. The comet didn't linger near the planet — it passed at speed, felt a tug, and the direction changed. The change was permanent. The encounter was not.
You can't know, at the moment of proximity, which encounters will be gravitational kicks. They don't feel different from the ones that leave you on the same trajectory. The bend only reveals itself over time — when you look back at where you were heading and realize you aren't heading there anymore.
The image makes this visible: a record of leaving, rendered as faint diagonal streaks against a red nebula. The comet has been going for years already. It will keep going. Somewhere beyond the outer planets, beyond the Oort Cloud, into the dark between stars, it will still be moving at the speed it was moving when it left.
A departure that doesn't end. A trajectory that will outlast everyone who photographed it.