how I rediscovered a small moon with a massive world

In the context of possible extraterrestrial life, Saturn’s moon Enceladus is one of the best candidates in our solar system. Enceladus, discovered by William Herschel in 1789, is only about 500 kilometers in diameter. This small size is deceiving. The moon is a world with many geological features that are similar to Earth. Enceladus has a thick and icy crust. As a result, the moon reflects nearly all the sunlight that hits it, making it one of the most reflective objects in the solar system. Perhaps one of the most intriguing things I have ever encountered is the fact that Enceladus harbors an ocean despite its freezing temperatures. This subsurface ocean remains in a liquid state due to the gravitational forces exerted by Saturn, which create tidal heating in Enceladus’ core. As the moon orbits Saturn, this frictional heating melts the ice and sustains the ocean, possibly for billions of years.

The Cassini spacecraft, which orbited Saturn from 2004 to 2017, provided incredible data on the moon that supported the possibility of life. Cassini has contributed most of the data that we currently have of Enceladus, which includes gravity, observations of the surface, etc.

One of the best discoveries credited to Cassini is the chemical makeup of Enceladus’ ocean. Using samples from the many geysers, Cassini detected molecular hydrogen and other compounds, suggesting that the moon’s ocean could host hydrothermal vents similar to those found on Earth. More recent findings of phosphates—an essential ingredient for DNA and cellular membranes—in Enceladus’ plumes further suggest that its ocean may contain the necessary components for life.

Moreover, it also revealed that the four “tiger stripes” (fissures that shoot out icy particles, water vapor, and organic compounds) near the south pole were very young, approximately 10 – 1000 years old. The Jet Propulsion Laboratory (JPL) states that “these findings support previous results showing the moon’s southern pole is active. The pole had episodes of geologic activity as recently as 10 years ago”.

Now that I’ve covered some contextual information, my team needs to design a vehicle that can do something?

We now have to consider the challenges of living on the moon. Any sustainable habitation of Enceladus would be extremely challenging due to its harsh environment. The surface temperatures average around -201°C (-330°F). The thick ice shell over the ocean, estimated to be more than 20 kilometers in some regions, poses a major barrier to accessing the ocean directly. This problem is slightly fixed by the “tiger stripes” on the south pole, as they have an average temperature of approximately -177.7°C (-279°F) and a thinner crust of approximately 2km – 5km. However, the massive eruptions of water and other particles that shoot up to 500km into space are another problem altogether.

Furthermore, Enceladus only has a gravitational pull of 0.113m/s2, 1/87ths of Earth’s, which Cassini measured over the course of three flybys of the surface. The lower gravity results in weakened muscles, reduced bone density, and bodily fluids shifting towards the brain. Drawing from these challenges, we can successfully define a problem statement.

A team of astronauts must travel 10 kilometers on Enceladus safely while combatting the icy temperatures and brightness-induced low visibility. They must also avoid geysers of water vapour and the possibility of escaping from Enceladus’s gravity pull.

Since my team now has a well-defined problem statement, we can now brainstorm some ideas to achieve our goal. The vehicle our team builds must include a solution to all of the problems defined. Firstly, to combat the extremely cold temperatures, the vehicle must have some sort of thermal system that functions despite the harsh environment. This system needs to allow all of the machinery and humans in the vehicle to function and not get damaged/hurt. Next, the vehicle needs some sort of energy source. This will most likely come in the form of the geothermal processes on the moon as the main energy sources we find on Earth are not available. Finally, to efficiently travel on the terrain, our vehicle needs grippy tires. Currently, I think that the best option would be to have steel hooks that would pierce into the ground and give the vehicle a grip on the ice.

No AI was used when writing or researching for this blog post.

Bibliography

• edeatrick. (2016, June 21). Saturn moon Enceladus’ ice shell likely thinner than expected. GeoSpace. https://blogs.agu.org/geospace/2016/06/21/saturn-moon-enceladus-ice-shell-thinner-expected/
• J. Hamilton, C. (n.d.). Saturn’s Moon Enceladus. Solarviews.com; Calvin J. Hamilton. Retrieved November 8, 2024, from https://solarviews.com/eng/enceladus.htm
• Jet Propulsion Laboratory (JPL). (2005, August 30). Cassini Finds Enceladus Tiger Stripes Are Really Cubs. NASA Jet Propulsion Laboratory (JPL). https://www.jpl.nasa.gov/news/cassini-finds-enceladus-tiger-stripes-are-really-cubs/
• Kohler, S. (2015, October 2). Geysers from the Tiger Stripes of Enceladus. AAS Nova. https://aasnova.org/2015/10/02/geysers-from-the-tiger-stripes-of-enceladus/
• NASA. (2018, September 25). Enceladus | Science. NASA Solar System Exploration. https://solarsystem.nasa.gov/missions/cassini-hds/science/enceladus/
• Postberg, F., Sekine, Y., Klenner, F., Glein, C. R., Zou, Z., Abel, B., Furuya, K., Hillier, J. K., Khawaja, N., Kempf, S., Noelle, L., Saito, T., Schmidt, J., Shibuya, T., Srama, R., & Tan, S. (2023). Detection of phosphates originating from Enceladus’s ocean. Nature, 618(7965), 489–493. https://doi.org/10.1038/s41586-023-05987-9
• The European Space Agency. (2017, November 6). Heating ocean moon Enceladus for billions of years. Www.esa.int. https://www.esa.int/Science_Exploration/Space_Science/Cassini-Huygens/Heating_ocean_moon_Enceladus_for_billions_of_years
• Waite, J. H., Glein, C. R., Perryman, R. S., Teolis, B. D., Magee, B. A., Miller, G., Grimes, J., Perry, M. E., Miller, K. E., Bouquet, A., Lunine, J. I., Brockwell, T., & Bolton, S. J. (2017). Cassini finds molecular hydrogen in the Enceladus plume: Evidence for hydrothermal processes. Science, 356(6334), 155–159. https://doi.org/10.1126/science.aai8703