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Closest Approach Next 10 Interstellar Objects


As of November 2021, two interstellar objects have been identified. With more powerful all-sky telescopes such as the Vera Rubin Observatory set to commence operations within a few years, the prospects for detecting interstellar objects will only increase. The anomalous `Oumuamua was intrinsically dim and would not have been detected had its closest approach been much farther than its value of 0.16au. Borisov, however, had a brightness-boosting "coma" (i.e. tail) that allowed for it to be easily identified despite only approaching 1.9au from Earth. `Oumuamua's close approach suggests that the population of small objects such as `Oumuamua may be far larger than the population of larger Borisov-like objects. The closest approach distance of the next identified interstellar object can be used as an inverse proxy for the typical intrinsic brightness of these objects, and also for the number of these objects that exist in the galaxy.

How close to Earth will the next 10 Interstellar Objects pass?

This question will resolve as the median of the closest approach distances (in astronomical units) to the Earth of the next 10 Interstellar objects, as determined by the orbital solution published by the Minor Planet Center. An object will be considered "interstellar" when it is given the "I" label by the Minor Planet Center.

By "next 10 Interstellar Objects", we mean the 10 objects labeled "Interstellar" by the Minor Planet Center, in the order they were classified, following 'Oumuamua and 2I/Borisov. If 10 new ISOs are not discovered by 2032-01-01, this question will resolve as the median of all new ISOs discovered up until then.

This question will close retroatively 24 hours before the classification of the first new ISO. If no interstellar objects are discovered by 2032-01-01, then this question will resolve ambiguously. Resolution may be delayed by a month or more to confirm the classification of any ambiguous objects.

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