Scientist for a Day

Tankut Timin

School: Çanakkale Koleji Özel Anadolu Lisesi

Class: 11

Teacher: Ayşe Gül Coşkun

Topic: Charon

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"Charon, with half the diameter and eighth the mass of Pluto, is its largest moon. Charon's volume and mass allow for calculation of its density (1.702 ± 0.017 g/cm³) which lets us determine that Charon is less dense than Pluto which consists of about %70 rock while Charon’s structure suggests a composition of %55 rock and %45 ice. Charon's surface appears to be dominated by the less volatile water ice compared to Pluto’s surface which is composed of nitrogen and methane ices. In 2007, Gemini Observatory observed patches of ammonia hydrates and water crystals on the surface of Charon which suggests the presence of active cryovolcanoes or cryo geysers. I think that these crystals had to be generated recently because otherwise, they would degrade into amorphous ices because of solar radiation. I also think Charon may have liquid pockets or internal seas/oceans beneath its icy surface to generate energy for its geological activities.

A notable structure of Charon is the Kubrick Mons, a mountain inside a moat that has a depth of 1 to 2 kilometers below the surrounding area. While how this mountain was formed is not known, however, it is speculated that Kubrick Mons may be a cryovolcano and the moat may be a result of a shrinking reserve of water and ammonia. All three of these mountains are quite close together, and two of them are on the Vulcan Planum plain. I think all of these mountains are connected to a large internal ocean underneath the icy surface of Charon as the energy needed for these geological activities can be generated from the tidal action on the ocean. If an ocean like that exists, it may provide a suitable environment for life on Charon.

The north polar region of Charon is dominated by a large dark area dubbed “Mordor Macula” by the New Horizons team. Their explanation for this phenomenon is that they are formed by the condensation of gases that have escaped Pluto’s atmosphere. In winter Charon’s temperature averages around -243°C and these gasses when exposed to this temperature condense into their solid forms, when they are exposed to solar radiation may react to form various tholins. Later when Charon’s seasons change and the temperature rises to -213°C the chemicals sublimate and escape from Charon’s atmosphere leaving the tholins behind. These tholins, in the presence of water, can be raw materials for prebiotic chemistry. I think their existence increases the probability of simple life forms on Charon and I believe this possibility should be investigated.

I think a spacecraft sent to Charon should focus on collecting samples of its ice, sampling organic materials and detecting it’s source of energy. I believe Charon’s geological activities are powered by tidal forces on the internal liquid reserves as we have seen evidence of liquid pockets on Charon’s surface. I think it should also prioritize detecting primitive life forms or at least any environments that can sustain them."