As it turns out, a recent coronal mass ejection (CME) is heading directly toward the interstellar comet ATLAS! And amateur astronomers are now asking: how often does something like this happen? Almost never — which makes it well worth watching.
According to NASA’s forecast model, the CME that erupted on September 19 is expected to reach comet 3I/ATLAS on September 24 or 25. It’s known that CMEs colliding with comets in the Solar System can bend or even sever their tails. What will happen to an interstellar comet remains anyone’s guess.
The timing is fortunate. The potential impact will occur just a week before the comet disappears into the Sun’s glare, giving astronomers a narrow window to capture the event. It also coincides with a recent brightening of the comet — a 40-fold increase in brightness since early September.