NASA's probe has traveled billions of miles, but it still hasn't reached the 'limit.'

The New Horizons probe, launched in 2006, has reached a distance that is 60 times greater than that of Earth to the sun, a remarkable milestone recently announced. This advancement means that the probe has doubled the distance it reached in 2015, when it took photographs of Pluto and its moons. However, there may be an even more fascinating aspect regarding the journey of this brave probe: it has not yet reached the outer boundary of the Kuiper Belt, a region beyond Neptune filled with comets and numerous icy worlds. This distant sector is comprised of remnants from the era when the primitive planets were forming.

The spacecraft was expected to reach the boundary of this belt approximately 1 billion miles ago. Wes Fraser, one of the project researchers, mentioned that the idea that the Kuiper Belt of our solar system is relatively small compared to other planetary systems may have arisen from a bias in observations.

Despite traveling 300 million miles a year, the New Horizons team has continued to gather information about the Kuiper Belt. Using Japan's Subaru telescope in Hawaii, scientists have detected a population of previously unknown celestial objects, which could be distributed nearly 90 times the distance from Earth to the sun, according to a recent study published in a planetary science journal. This discovery suggests that the Kuiper Belt may extend much farther than previously thought, or even that another belt may exist even further out.

If this finding is confirmed, it could mean that New Horizons still has a long way to go before approaching interstellar space, the region beyond the influence of the constant flow of material from the sun. This space was marked by New Horizons' arrival at a Kuiper Belt object known as Arrokoth in January 2019, which is the most distant object found by a spacecraft, at approximately 4 billion miles from Earth.

The future of the probe is promising, as it is estimated to have enough energy and fuel to continue operating at a distance 100 times greater than that of Earth to the sun until at least 2050. Alan Stern, a planetary scientist in charge of the mission, comments that if New Horizons manages to survive until it reaches interstellar space, it would not be the first probe to do so, as the Voyager 1 and 2 probes, launched in 1977, have already exited the solar system.