Thalassa

==Overview==
Thalassa, sometimes referred to as Neptune IV, is Neptune's second-closest satellite and it's the 7th largest Neptunian satellite with regard to size. It was previously designated as S/1989 N 5 before being given a proper name by the IAU. It was most likely created when Triton, after being recently captured, gravitationally disturbed one of Neptune's original moons, triggering the destruction of Neptune's prior big moons and the emergence of smaller, second-generation moons, one of which was Thalassa.https://www.sciencedirect.com/science/article/abs/pii/001910359290155Z?via%3Dihub Thalassa was named after the sea goddess Thalassa in Greek mythology.https://solarsystem.nasa.gov/moons/neptune-moons/thalassa/in-depth/
==Discovery==
One of the numerous photographs obtained by Voyager 2 during its stellar voyage to Neptune includes Thalassa, although the little moon wasn't identified until the middle of September 1989 by the Voyager Imaging Team. On September 29, 1989, the discovery was made public. After the discovery, the moon was given the provisional designation S/1989 N 5.http://www.cbat.eps.harvard.edu/iauc/05300/05347.htmlhttp://www.cbat.eps.harvard.edu/iauc/04800/04867.html On 16th of September, 1991, the IAU officially named the Neptunian satellite Thalassa after the sea goddess.
==Physical characteristics==
Thalassa is presumed to have been formed by a few small fragments of Neptune's previous major moons. It has an approximate diameter of 62.29 km and an uneven form as a result of its small size. For an irregular body, it looks to be roughly disk-shaped, which is unusual.
==Motion==
Thalassa orbits Neptune at an estimated distance of about 25300 km and Thalassa completes orbit around Neptune every 7 hours and 28 minutes. Another Neptunian satellite, Naiad, is in a 73:69 orbital resonance with Thalassa. From Thalassa's perspective, Naiad seems to pass Thalassa's orbital plane as it crosses it twice, once above and once below, in a cycle that occurs when Naiad gains four laps on Thalassa, or 21.5 Earth days. Thalassa and Naiad's orbits are stabilized by this unique resonance.https://www.jpl.nasa.gov/news/nasa-finds-neptune-moons-locked-in-dance-of-avoidance Given its close proximity to its primary planet, Neptune, it is probable that it is tidally locked to that planet, with one side facing Neptune and the other facing away. Due to Thalassa's orbit being located below Neptune's synchronous orbit, tidal dissipation is bound to happen in the foreseeable future. It is probable that Thalassa would either disintegrate when it moves through the thick Neptunian atmosphere or fracture off, resulting in a new planetary ring encircling Neptune upon passing the Roche limit.
==Gallery==
File:Thalassa-001.png|Thalassa and Despina
File:Naiad-Thalassa-Despina-main.png|Naiad, Thalassa and Despina (Thalassa being middle)
Category:Real objects
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Category:Solar System
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