An article accepted for publication in the “Planetary Science Journal” reports the detection of 239 candidate trans-Neptunian objects (TNOs). NASA’s New Horizons Kuiper Belt search team discovered the candidates using the Subaru telescope in Hawaii. Estimates indicate that the candidates are located at distances up to 90 times that of the Earth from the Sun. This supports the theory that the Kuiper Belt is wider than expected or that there’s a second Kuiper Belt further out.

A few months ago, a paper published in “The Astrophysical Journal Letters” based on dust detections by the New Horizons space probe suggested the possibility that the Kuiper Belt is wider than astronomers thought or that there’s a second Kuiper Belt.

New Horizons continues to travel through that area of ​​the solar system far beyond Pluto moving away from the Sun, but its mission isn’t over yet. The space probe continues to conduct surveys, and the mission team has been looking for potential new targets that fit its trajectory since its beginning. This research has offered interesting results.

The Subaru telescope was used in an astronomical survey to search for trans-Neptunian objects, the ones within the Kuiper Belt. The Hyper Suprime-Cam, a giant camera installed on the telescope, allowed 239 candidates to be found. At billions of kilometers away, there’s always the possibility of stumbling into some false positives, so it will be necessary to verify that those objects are really asteroids. However, their number is truly remarkable exactly because of their distance.

The New Horizons space probe is now at a distance from the Sun that is about 60 times that of the Earth. For some time now, the fact that it’s still in the Kuiper Belt had caused surprise because the knowledge that was mainly indirect that existed in the past suggested that that area was relatively narrow. The discovered candidates are up to 90 times the distance of the Earth from the Sun. In short, they are confirmations that the Kuiper Belt is wider than expected or that there’s another, more external one.

The study of other solar systems indicated the presence of Kuiper Belts much more extensive than the width that was estimated for the solar system’s Kuiper Belt. These recent studies suggest that the solar system is not anomalous.

It may seem paradoxical that Kuiper Belts light-years away are known in some ways better than one that is “only” a few billion kilometers away. The problem lies in observing it from the internal solar system, where it’s impossible to obtain the overall vision of a generic agglomeration of asteroids and dwarf planets that is possible by observing another star system.

The verification of the candidates discovered in the Kuiper Belt will also serve to obtain estimates of their orbits. The researchers hypothesized that there’s a gravitational bond with the planet Neptune but this too will have to be verified. Given the distance of these objects, observations conducted over long periods of time are needed to obtain precise estimates. That’s a well-known problem in the search for other possible planets in the Kuiper Belt that led to very different results, disputed by those who claim that the known objects are sufficient to generate gravitational bonds attributed to hypothetical planets.

It’s possible that only asteroids will be confirmed but this will still be useful to better understand the extension of the solar system and the processes that led to its formation. It might be impossible for the New Horizons space probe to perform more flybys but this study is still useful for astronomers and could have many follow-ups.