Destroyed worlds: NASA's chilling discovery at the edge of the solar system
It moves in the opposite direction, holds 99% of the mass, and tore the other moons to shreds. The James Webb Telescope reveals the greatest disaster in Neptune's history. Data that stunned the researchers.
Small moons of Neptune and the dust rings surrounding the planet may be remnants of an ancient world that broke apart billions of years ago. This emerges from a new analysis of observations from NASA's James Webb Space Telescope, in which magnesium-rich clay minerals were identified — a sign of processes that occurred in the past inside much larger bodies.
The study, published in the scientific journal Science Advances, points to the possibility that Neptune's large moon, Triton, which was captured in the past by the planet's gravity, triggered a chain of collisions that destroyed Neptune's ancient moon system and recreated the small moons we see today.
The researchers identified the magnesium-rich minerals in Neptune's small inner moons — Proteus, Larissa, and Galatea — as well as in the planet's inner dust rings. According to the researchers, minerals of this type are formed after prolonged interaction between liquid water and rock. The difficulty is that Neptune's small, cold moons cannot currently sustain such conditions themselves. Therefore, the researchers estimate that the materials came from larger bodies that were destroyed in the past, when the interiors of the ancient moons were exposed and scattered into space.
Neptune is located at a distance of about 30 times the distance from the Earth to the Sun, and it is surrounded by 16 known moons. Its moon system is different from that of Jupiter, Saturn, and Uranus, where the large moons move in relatively orderly orbits around the planets.
In Neptune's case, the situation is more unusual — Triton alone contains more than 99% of the total mass of the planet's moon system.
According to the researchers, the central explanation for the unusual structure is Triton itself. It is estimated that the large moon formed further from the Sun, in the Kuiper Belt region — a distant area in the solar system where many icy bodies are found — and was captured by Neptune's gravity during the first turbulent period of the solar system, within the first billion years after its formation (about 4.5 billion years ago).
After its capture, Triton's gravity likely destabilized Neptune's ancient moons and caused them to collide with each other. The fragments created from the collisions later merged and formed the small moons and some of the material that makes up the rings today.
One of the signs supporting the theory is Triton's unusual orbit: it orbits Neptune in the opposite direction to the planet's rotation — a movement known as a "retrograde orbit." This characteristic strengthens the possibility that it did not form where it is today.
"The interiors of large icy moons are usually completely hidden from us, buried beneath thick layers of water ice and accessible only through models and inferences," said Riley Davis, a planetary scientist who led the study. According to her, in Neptune's case, the ancient collision "effectively turned these ancient worlds inside out," allowing researchers to examine materials that would otherwise have remained hidden.
The researchers note that there is also an alternative possibility: another body similar in size to Pluto from the Kuiper Belt came too close to Neptune and was torn apart by its gravity. However, they estimate that this scenario is less likely than the possibility of Triton's capture.
The researchers emphasize that the findings do not definitively prove the scenario, but they strengthen the assessment that a single, unusual event could have completely changed the structure of an entire moon system. "This is a vivid example of how one random event can fundamentally change the architecture of a planetary system," said Davis.
