![]() ![]() The new research calculates how the thickness of the ice shell can influence the tidal dissipation and thus the crystallization of the subsurface ocean. Investigating how the shape of the orbit evolved through time is important to determine the level of tidal heating that occurred, and thus if the subsurface ocean could still exist today.Īs Triton cools, the ice sheet will grow to engulf the underlying ocean. Triton’s orbit is currently almost exactly circular. The exact point in time when Triton was captured by Neptune and the length of time it took for the moon's orbit to become circularized are unknown. ![]() This computer generated montage shows Neptune as it would appear from a spacecraft approaching Triton, Neptune's largest moon. "Radiogenic heating, in comparison, heats up the shell uniformly, and thus doesn't have as disproportionate an influence as tidal dissipation does." Said Saswata Hier-Majumder at the University of Maryland. "While the concentration of tidal dissipation near the bottom of ice shells was known for some time, we believe our work is the first to demonstrate that it indeed controls the rate of freezing and sustainability of subsurface oceans," This tidal dissipation is stronger for larger values of eccentricity, meaning it would have played a major role in heating Triton in the past. Radiogenic heating contributes several times more heat to Triton’s interior than tidal heating however, this heat alone is not sufficient to keep the subsurface ocean in a liquid state over 4.5 billion years.īut tidal dissipation causes heat to be concentrated at the bottom of Triton's ice shell, which impedes the growth rate of the ice and effectively acts as a tidal-heated blanket. This is heat produced by the decay of radioactive isotopes within a moon or planet, and this process can create heat for billions of years. The energy loss from tides is also responsible for gradually changing Triton’s orbit from an ellipse to a circle, researchers say.įriction from tides is not the only source of heat within a terrestrial body there is also radiogenic heating. The energy loss is converted into heat within the moon, and this heat may have melted some of the icy interior and formed an ocean beneath Triton's ice shell. This type of orbit would have raised large tides on the moon, and the friction of these tides would have caused energy to be lost. Triton likely originated in the Kuiper Belt - the ring of icy bodies beyond Neptune - and was sent hurtling inward until it was captured by Neptune’s gravity.ĭirectly after capture, the moon would have been in a highly elliptical, eccentric orbit. The early solar system was a place of dynamic violence, with many bodies changing orbits and crashing into each other. The retrograde orbit of Triton means that it most likely did not form around Neptune. These orbits are known as prograde, and a rogue object that orbits backward is said to be in a retrograde orbit. This disc circles the star in one direction, and thus most planets and their moons orbit in this same direction. Planets form from a circumstellar disc of dust and gas that surrounds a young star. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |