Oshadha Perera

Oshadha Perera

Grade: 10 (US 9th Grade)

School: Southland Boys High School

Teacher: Julia Shannon

City: Invercargill

Topic: Triton


"Being the largest moon of Neptune, Triton has attracted the interest of humans, from professional scientists to astronomy enthusiasts since it was discovered by the British astronomer William Lassell in 1846.

Triton is a main astrobiological target in the search for alien life. It was identified as the prime candidate in the Roadmaps to Ocean Worlds study in 2019. Trident was proposed to the NASA Discovery Programme in 2019, whose proposal includes a thorough analysis of Triton and why a mission to Triton would be important.

Artist's view of Voyager 2 at Triton
The possible existence of a sub-surface ocean is the most compelling feature of Triton, which would if confirmed, drag the habitable zone to approximately 29AU. While conditions necessary for an internal ocean prevails, it remains for a future mission to prove the existence of one.

Crater counts suggest that Triton’s surface is the second youngest planetary body in the solar system, with less than 10Ma of age. Images of Triton’s southern sub-Neptune hemisphere were taken by Voyager 2, on its journey to the Kuiper Belt in 1989. By applying photogeology to these images, scientists have concluded that Triton has an endogenic interior with a network of tectonic structures, several cryovolcanic landforms, extensive cantaloupe terrain and several particulate plumes and associated deposits. This establishes Triton as a geologically active planetary body.

Scientists suggest that Triton has enough heat to maintain an internal ocean. Heat sources include,

• Radiogenic heat

• Heat preserved from being captured to Neptune’s orbit – Triton is confirmed as a captured Kuiper Belt Object

• High axial tilt

• Tidal activity

Triton’s atmosphere consists mainly of nitrogen, in addition to carbon monoxide and methane. A polar cap, probably containing nitrogen, was observed. The presence of methane facilitates the production of organic materials, especially if it comes into contact with liquid water, which supports life.

While Triton’s atmosphere is exceptionally thin, scientists suggest that it is sufficient to be a major sink for volatile substances and dynamic enough to support movement.

Equipment to be included in a mission should strive to detect internal oceans and their properties, observe changes, map the surface, to detect liquid particles in Triton’s plumes and to detect energy outputs to its atmosphere. Wide and narrow angled cameras, magnetometers, infrared spectrometers and a radar system would be some examples for equipment able to perform those functions. Trident suggests using a plasma spectrometer to investigate the ionosphere and radio science, while Roadmaps to Ocean Worlds mentions UV spectroscopic imaging to study Triton’s plumes.

The main objective of a mission to Triton would be to confirm the existence of a sub-surface ocean that could host life. Trident identifies explanations on Triton’s young geological age and intense ionosphere as factors to be explored while investigating the geyser plumes of Triton would also be beneficial. Finding answers to these questions as well as extra information would lead to more specific and accurate hypotheses on one of the most sought-after suspicions of mankind: Does alien life exist in our solar system?"

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