The article discusses the scientific accuracy of the movie "The Martian" specifically focusing on the scenes where the protagonist, Mark Watney, grows potatoes on Mars using his own feces as fertilizer. The author initially questions the possibility of survival on a diet of only potatoes, but research reveals that potatoes are a surprisingly nutritious food source, lacking only a few essential vitamins and minerals.
The use of feces as fertilizer is also explored, and it is found that this practice, known as "night soil," has been used for thousands of years. However, the author notes that using raw human feces as fertilizer can be problematic due to the presence of pathogens. Fortunately, in the Martian environment, the feces would be freeze-dried and exposed to harsh conditions, killing off the pathogens.
The biggest challenge to Watney's survival is found to be the presence of perchlorates in the Martian soil, which can disrupt the body's metabolic systems and increase the risk of thyroid cancer. However, calculations suggest that Watney's exposure to perchlorates would be within safe limits, and even if it were not, the perchlorates could be easily removed by washing the soil.
Overall, the article concludes that the science behind the movie's portrayal of growing potatoes on Mars is surprisingly accurate, and the author praises the film for its attention to real-world science.
Here are the key facts extracted from the text:
1. NASA found water on Mars the same week the movie "The Martian" was released.
2. The Martian atmosphere is only about 1% the thickness of Earth's atmosphere.
3. The winds on Mars are much weaker than on Earth, even during the worst storms.
4. The worst storms on Mars would not be enough to register as a category 1 hurricane.
5. Mark Watney, the astronaut in the movie, grows potatoes on Mars to survive.
6. Potatoes are a versatile food that can provide almost all the nutrients the human body needs to survive.
7. A man named Chris Voy ate only potatoes for 60 days to prove it was possible.
8. Humans can survive on potatoes alone, but would need occasional supplements to avoid deficiencies.
9. Using human feces as fertilizer, also known as "night soil," has been practiced for thousands of years.
10. As of 2013, 55% of US sewage solids were turned into fertilizer.
11. The Martian soil lacks bacteria that fix nitrogen, making it less conducive to plant life.
12. Matt Damon's character uses his own feces to fertilize the soil on Mars.
13. The Phoenix Mars Lander found that Martian soil contains about 6% perchlorate, a salt that can disrupt the body's metabolic systems.
14. Perchlorate can interfere with the body's ability to absorb iodine, affecting thyroid hormone production.
15. Long-term exposure to perchlorate can increase the risk of thyroid cancer.
16. According to the Environmental Protection Agency, a typical human consumes about 100 mg of dirt per day.
17. Mark Watney's exposure to perchlorate on Mars would likely be within safe limits, according to the Agency for Toxic Substances and Disease Registry.
18. Washing the Martian soil could remove the perchlorate, making it safe for use.