Melodi Sıla Bozkaya

Melodi Sıla Bozkaya

Grade: 11

School: Eyüboğlu Koleji

Teacher: Burcu Parmak Yıldırım

Topic: Triton


"The 1989 Voyager 2 flyby of Triton’s south pole photographed pummels of dusty material being jetted into space which indicated the existence of cryovolcanism in the form of ice geysers and showed that Triton was geologically active. Triton also has a unique feature in its retrograde orbit which hints at the possibility that Triton was once an object of the Kuiper Belt captured by Neptune, leading to tidal heating. Furthermore, internal radiogenic heating exists within the moon. The existence of geological activity coupled with internal heating hints at a subsurface ocean and, in my belief, an ocean that could harbor life in the form of microorganisms.

Artist's rendering of Voyager 2 and Triton
The first point to cover is the retrograde motion of Triton around its planet. The moon and Neptune should have been performing prograde motion had they formed at the same time. One theory for this is that Triton was once outside Neptune’s system and was captured by its gravity. Although Triton has a circular orbit around Neptune today, it would most likely have had an elliptical orbit after the capture. This would indicate that the distance between the two objects changed constantly which would have resulted in tidal forces and heating. Much like Europa, Triton might’ve warmed up considerably and this might’ve caused the icy material near the core to melt, forming an ocean. However, as the orbit of Triton became more circular, the tidal heating would’ve decreased, and the moon would’ve started to freeze again.

The existence of cryovolcanism tells us otherwise. Evidence shows that the ice geysers on Triton can pummel material as far as 8 km, which requires a powerful driving force. In order for the geysers to form, such a force in the form of an ocean might be possible. Consequently, an alternative method for sustaining the ocean might be the radiogenic heating resulting from the radioactive decay within the core.

Finally, the composition of the ocean should also be considered. Research shows that the ocean would be ammonia rich with the concentration of at least %15. Thus, any life within the ocean would have to use ammonia as a solvent instead of water. However, the oxidation of ammonia would cause it to break down, so any life requires an anaerobic metabolism. Certain prokaryotes such as archaea already perform this.

The chemical composition of possible life on Triton, does not have to be in a familiar form. Carbon based life is the only life that is known so far, however a recent study created enzymes which produced organo-silicon compounds. The enzymes were much more efficient after undergoing mutations. It is important to note that silicon would also be more compatible with ammonia. Silicon and oxygen have a very high affinity which results in a silica shell. If silicon-based life is to form, such a reaction needs to be avoided. An ammonia rich subsurface ocean in Triton holds the potential for unusual life and warrants further research. Exploring Triton might lead us to finding different life forms in the Universe."

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