“a star cluster” ... “a dozen light years across” ... is heading for Earth ... and this broad cluster ... “is expected to endlessly drift through space” ... “rocketing.”
Doesn’t really sound like it will:
a) drift
b) endlessly
Given its speed of “more than two million miles per hour” and that it’s *not* “generally in the direction of earth” but *IN THE DIRECTION of earth.*
Given how broad the cluster is, it sounds like earth is pretty much in the path.
Given that, “endlessly” also does not sound likely?!
Well, we may know how fast and which direction it was headed when the light was produced, but how long did it take for the light (showing the cluster and it’s vector) to get here? Whatever we watch at a distance has already happened, it takes time for the view to arrive.