Astronomers See Stars Slinging Comets at Earth for the First Time


Oct 22, 2019
I was glad to read this report and some others too. An important comment in the report says "In our study, we discovered only two cases in which this actually happened, and yet, we observe dozens of comets every year," lead study author Rita Wysoczańska, an astronomer at the Institute Astronomical Observatory at Adam Mickiewicz University in Poland, told Live Science. "At this moment, we can say that the mechanism proposed by Oort is not sufficient enough to generate all comets we observe." It's likely that the collective gravitational force of more distant stars can boost comets into long-period orbits. And once a comet enters the solar system, it can be further perturbed by the planets therein."

The Oort Cloud is not imaged directly by telescopes. Long period and short period comets have limited lifetime in the solar system (e.g. perihelion passages and mass loss), their rates of disintegration point to a recent origin or entry into the solar system.