Scientist for a Day

Vlad Manolescu

School: Gymnasium School No. 156

City: Bucharest

Topic: Triton

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"Neptune’s moon Triton is a fascinating object, a dynamic moon with atmosphere, and geysers. It is Neptune’s largest moon and is the only moon in the solar system to orbit in the opposite direction to its planet’s rotation, a retrograde orbit.

Triton has density (2.061 g/cm3), temperature and chemical composition similar to that of Pluto. Because of this, and the fact that it circles Neptune in a retrograde orbit, astronomers believe that the moon originated in the Kuiper Belt and later became trapped by Neptune’s gravity. Recent studies have also shown that its arrival likely destroyed Neptune's existing moons, the debris of which combined to form what we see there today.

Also like Pluto, 55% of Triton’s surface is covered with frozen nitrogen, with water ice comprising 15–35% and dry ice (also, frozen carbon dioxide) forming the remaining 10–20%. Trace amounts of methane and carbon monoxide ice are believed to exist there as well, as are small amounts of ammonia (in the form of ammonia dihydrate in the lithosphere).

Seasonal changes are a result of Triton's tilted orbit around Neptune (~23°, relative to the equator), which causes one hemisphere to experience summer while the other experiences winter. When one hemisphere is experiencing summer, the frozen nitrogen, methane, and carbon monoxide on Triton's surface sublimates into gas, which thickens the atmosphere.

When the seasons change, which happens every 40 years, this gas then freezes and descends to form ice on the surface again. A mission on Triton will be able to get a more complete picture of seasonal changes on the moon.

These activity are the result of Triton being geologically active, unlike most Solar moons. This results in cryovolcanism, where liquid ammonia and nitrogen gas burst through the surface and send material to altitudes of up to 8 km (5 miles). Investigating these activities will reveal more things about Triton's subsurface environment, which is believed to harbor an interior ocean.

Much like other moon, Europa, Ganymede, Enceladus, Titan, Ceres and other bodies in the solar system, this ocean is believed to be the result of geothermal heating at the core-mantle boundary. Combined with the presence of organic molecules, the presence of liquid water and energy could also mean that Triton is capable of supporting life.

A mission on Triton will be able to get a more complete picture of seasonal changes on the moon and would be interesting for exploration of ocean worlds in our solar system in the hopes of finding evidence of life, and would also help resolve ongoing questions about the origin of this mysterious moon.

Maybe, with help for this mission will be learn more about the formation and evolution of the solar system and we might even find indicators of extra-terrestrial life, which will be the greatest discovery in the history of space exploration."