Neptune
Neptune is a planet in the Solar System. At 14 Earth masses, it's the smallest of the gas giants, and also the furthest from the Sun.[1] As of 2026[update] sixteen moons have been discovered orbiting Neptune. The length of a day is nineteen Earth hours. Neptune, like Planet Jupiter and Planet Uranus, has rings, but much more tenuous than those of Planet Saturn.
Unlike the Solar system's other seven planets Neptune was first discovered by analyzing that an as yet unknown planet was perturbing the orbits of other planets.[1] Based on calculation of those perturbations Astronomers were directed where to look for Neptune.
Neptune was photographed by the Voyager 2 space probe, and for decades images of Neptune were incorrectly shown as a deep blue.[1]
Its largest moon, Triton, has a retrograde orbit -- it orbits in the "wrong direction".[1] It is widely accepted that Triton is a captured Kuiper Belt Kuiper belt object, like Pluto
It is now believed that the capture of Triton triggered a "moonpocalypse".[1] The capture of Triton is now believed to have caused the loss of all Neptune's original moons, with the exception of Neried, the second largest moon. Nereid has a very eccentric orbit, and it too was posited to be a captured Kuiper Belt object, but recent spectroscopic analysis of the reflected light from Neried suggest it is Neptune's sole original moon.[2] Its eccentric orbit is now attributed to the disruption caused when Triton was captured.
All the Solar systems other planets rotate around axes that point more or less perpendicular to the plane the planets orbit.[1] Neptune orbits on its side, and has unusual magnetic poles, also attributed to the disruption caused by the capture of Triton.
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 1.4 1.5
Anton Petrov (2026-07-06). "Studies on Neptune Challenge Assumptions About Its Composition and Moons". What da Math. Archived from the original on July 6, 2026-07-06. Retrieved 2026-07-06 – via YouTube. Check date values in:
|archivedate=(help) - ↑
Matthew Belyakov; M. Ryleigh Davis; Ian Wong; Konstantin Batygin; Michael E. Brown (2026-05-22). "Nereid as a regular satellite of Neptune". Science Advances. 12 (21). doi:10.1126/sciadv.aeb1429. ISSN 2375-2548. PMC 13189092 Check
|pmc=value (help). PMID 42160409 Check|pmid=value (help). Retrieved 2026-07-07.Nereid’s unique spectrum among outer solar system bodies is not consistent with a scenario where Nereid is captured during the early Solar System’s dynamical instability (12). The combination of a bright, water icy surface with a unique dark material renders Nereid unlike KBOs or other irregular satellites like Phoebe, suggesting that Nereid did not form in the outer planetesimal disk alongside KBOs.