What can the discrepancy between the estimated number of Oort Cloud objects and the observed long-period comets tell us about solar system evolution?

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The fact that we predict billions of Oort Cloud bodies but only see a few dozen long‑period comets each year shows that many objects never leave the cloud, hinting that the cloud is largely inert and that the Sun’s gravity and passing stars rarely disturb it. This mismatch tells us that the outer Solar System is more stable and that the Sun’s early interactions with nearby stars or the Galactic tide are the main forces that occasionally send comets inward. Because the observed comets are a tiny, biased sample, we learn that the cloud must be very massive and that its evolution has been gentle, preserving most of its material. For example, if we expect a thousand comets per year but only see a handful, it suggests that the Sun’s motion through the galaxy has only recently begun to stir the cloud, revealing a long‑term, slow‑moving reservoir of icy bodies.

What can the discrepancy between the estimated number of Oort Cloud objects and the observed long-period comets tell us about solar system evolution?

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