Close Encounter with Another Star May Explain Solar System's Odd Celestial Orbits

Billions of years ago, a passing star may have come incredibly close to our Solar System, as revealed in new studies published in Nature Astronomy and The Astrophysical Journal Letters. This stellar flyby could explain the puzzling orbits of certain objects in our Solar System, including trans-Neptunian objects and irregular moons.

The Stellar Encounter

According to the findings, the wayward star approached within 110 astronomical units of the Sun (AU) or 110 times the distance between the Sun and the Earth. In perspective, this brings the stellar visitor closer to Earth than the current distance of the interstellar-bound Voyager 1 probe, which has managed to travel 164 AU away from our planet since its launch in 1971.

This close encounter could explain the chaotic orbits of trans-Neptunian objects and even the irregular moons of our neighboring gas and ice giants. The authors conducted over 3,000 computer simulations, which confirmed that an interstellar intruder's gravity could have caused the tilted orbits of these objects.