Mars is also much colder than Earth. This is mostly because the Red Planet is farther away from the sun than Earth. Also, just like on Earth, nutrients in Martian soil may vary from place to place. So, people stranded on Mars should be prepared to turn to ingenious ways for making the soil more suitable for plant growth—even if the only option is using their own feces, as Watney did. When soils are rich in nutrients—such as nitrogen, phosphorus, and potassium—crops grow well.
But when the soils are not as rich—with even just one of the needed nutrients in low supply—plants would not grow as well. These fertilizers also supply nutrients to the crops that some soils do not have. Here on Earth, experts encourage using organic waste, or manure, to fertilize soil, although U. Other sources of nutrients, such as organic food waste, are also useful. That is why, for example, some people mix banana peels or coffee grounds into soil in their gardens. On Mars, Watney did not have any man-made fertilizers available to him.
He was not planning to stay there for a long time, let alone having to farm there, so his feces acted as organic waste that contained nutrients. In fact, in earlier times, when technology was less advanced, farmers used their own sewage to provide important nutrients, such as nitrogen and phosphorous, to their land.
To create the energy they need to live, plants use a process called photosynthesis, which is a series of chemical reactions that convert water and carbon dioxide into sugars and oxygen. These chemical reactions can be summarized in the following way in this case, the sugar is glucose C 6 H 12 O 6 :.
To carry out photosynthesis, plants also need various nutrients, such as nitrogen, potassium, and phosphorus. Nitrogen is a key component of chlorophyll, the compound responsible for the green color of plants and for capturing the light needed for photosynthesis. Potassium helps to open and close tiny pores in leaves and stems that take in the water and the carbon dioxide used in photosynthesis. Phosphorus is involved in the chemical reactions that make up photosynthesis.
In contrast with plants, human beings and animals cannot harvest solar energy. Instead, humans obtain it from eating food, which comes from animals and plants and provides the energy we need to survive.
Animals also get their energy from plants or other animals that eat plants. In that sense, everything we eat was once a plant. It is not easy to predict what we will or will not be able to do when we set foot on Mars. Scientists have conducted plant experiments simulating Martian conditions using volcanic soil in Hawaii, which is known for its similarity to Martian soil. These experiments found that plants can actually grow in these soils.
There are other aspects future Mars explorers will need to consider when growing plants on that planet. Also, studies suggest that watering plants on Mars could require less water than on Earth. In other words, anything on Mars would feel about three times lighter than on Earth.
Therefore, under Martian gravity, the soil can hold more water than on Earth, and water and nutrients within the soil would drain away more slowly. Some conditions would make it difficult for plants to grow on Mars. Sunlight and heat reaching that planet is much less than what the Earth gets.
This is because Mars is about 50 million miles farther away from the sun. However, Watney was clever enough to think of a way to make water from scratch and irrigate his potatoes. Making water does not sound like a complicated process: take oxygen, add hydrogen, and burn them together to create water. But Watney did not have hydrogen at his disposal. The oxygen, on the other hand, was easy to get. To obtain hydrogen, Watney used hydrazine N 2 H 4 , an inorganic compound widely used to propel rockets, satellites, and spacecraft that was available from his mission to Mars.
He had hundreds of liters of unused hydrazine. Watney dissociated hydrazine into nitrogen and hydrogen, and then, he burned hydrogen with oxygen, which resulted in water, as follows:.
Is it possible to create water from scratch? Not really, since creating water from scratch by burning hydrogen and oxygen would be too dangerous. It goes without saying: You should not try burning hydrogen and oxygen at home. Watney had no other available option, and he was extremely careful to burn hydrogen and oxygen slowly enough to avoid blowing himself up. Mars is considered the next frontier in human space flight. Scientists think the Red Planet could host or have hosted life millions of years ago.
It is the closest world to us that could host life, even if they are microbes. By the time humans set foot on Mars, you may be in the class of astronauts selected for their journey into the Red Planet. Watney had a difficult time during his visit to Mars, but it was chemistry that ultimately saved his life! Kinberg, S.
Producer ; Scott, R. The Martian [Motion Picture]. United States: 20th Century Fox, Mars: Extreme Planet. All About Mars. Mars Exploration. Hooper, R. New Scientist, Sept. Roberto Molar Candanosa is a science writer located in Washington, D. This is his first article in ChemMatters. For example, plants need large quantities of macronutrients to allow them to grow, harvest energy, and reproduce.
These macronutrients are carbon, hydrogen, oxygen, nitrogen, phosphorus, and potassium. Plants also take up carbon, hydrogen, and oxygen from air and water, while other macronutrients are taken up from organic and inorganic sources in the soil.
We see this in proteins and DNA, but it also shows up in smaller molecules, like lipids, which are assembled in two-carbon units — meaning that they tend to have even numbers of carbons 14, 16, 18 and so on. Isoprenoids — components of essential oils and pigments, including chlorophyll — are assembled in five-carbon subunits.
Even if these chemicals have broken down over time, their degradation products retain similar patterns. Biological processes — at least the ones we know — tend to work slightly differently, with compounds containing different isotopes of important atoms like carbon.
Editorial Reviews. About the Author. Cidney Swanson is a full-time writer of Young Adult Sci-Fi and Fantasy including The Rippler Trilogy and The Saving Mars. Mars Burning book. Read 21 reviews Mars Burning (Saving Mars, #4). Other editions Because I have to take time out of the next book in the series to write it.
Abiotic ones generally have no such preference. On Earth, this is most obviously the case with the two stable isotopes of carbon, 12C and 13C, with the heavier 13C isotope being disfavoured. It can even be used to determine if steroids and hormones in athletes suspected of being drug cheats are laboratory-synthesised or produced by their own bodies.
It is possible, of course, that a future rover might scoop up living organisms, rather than degraded chemicals contained in ancient rocks. But another way of searching for signs of existing life is by testing the Martian atmosphere for methane. On Earth, methane is mostly produced by biological activity, ranging from cow farts to decomposing plants. But it is also produced by geological processes, such as the interaction of water with a mineral called olivine in a process called serpentisation because it produces the green-coloured rock known as serpentine.
Then, in , Webster reported that six Earth years of measurements three Mars years by the Curiosity rover had found atmospheric levels of methane that peaked in the summer and dropped in autumn and winter — that might or might not suggest the presence of methane-producing microorganisms that wake up in warm weather, then go back into hibernation for the winter. We also know that the surface of Mars is extremely inhospitable, thanks to an atmosphere that is too thin to block out harsh radiation and high levels of oxidising chemicals such as perchlorates.
Recommended Scientists posit microbes on Enceladus and Mars Space. But the results of that will be mostly of interest to deep-interior geophysicists. Currently, oxygen is only 0. Not that oxygen is the only thing these organisms would need.
But the idea that there could be enough oxygen down there, today, to support a relatively complex ecosystem is nevertheless exciting. There is abundant geologic evidence that Mars was once warm enough to have liquid water. But did this occur over a long period of time, or in intermittent epochs?
That sounds like evidence for an initially thick atmosphere that might have taken a while to erode by enough to put the planet into the deep freeze. You might be constantly replenishing your wallet from the ATM, with only a few dollars at any time. It was chosen because it once hosted a lake, with a river draining in from the surrounding highlands to produce a large delta. Martin van Kranendonk, director of the Australian Centre for Astrobiology at the University of New South Wales, suggests that it is also possible to look for life signs at the types of places where life might have originated.