What does Titan smell like? Experts say the air of Saturn’s largest moon is filled with sweet musk, bitter almond, gasoline and rotten fish. Titan is the largest satellite of Saturn, and its size is comparable to that of Ganymede, making it the largest satellite in the solar system. If we stripped Titan’s atmosphere, Ganymede would be a little bigger. Titan, Saturn’s largest moon, is a dynamic world with a thick atmosphere, hydrocarbon lakes and many different odors. Although people don’t need special spacesuits to resist this pressure, people must need some outdoor warm clothing because the surface temperature of Titan is very cold, as low as – 179 degrees Celsius. By contrast, the lowest temperature recorded on earth is at Vostok station in Antarctica in 1983 It’s 89 degrees below zero. < / P > < p > when Huygens landed on Titan’s surface, it captured an amazing picture of Titan. If humans do arrive at Titan in the future, they may first notice not vision, but smell. < / P > < p > therefore, when astronauts walk on Titan’s surface, they have to cover their skin with heating materials to avoid rapid skin frostbite, but they don’t need the bulky spacesuits they wear on the moon or in a vacuum. Since there is no oxygen in Titan’s atmosphere, which is mainly composed of nitrogen, and about 5% of methane and some other trace gases, astronauts must carry their own oxygen. < / P > < p > if you’re going to travel Titan, you can imagine people wearing similar clothing that Antarctic researchers wear in winter, which might include clothes with multiple insulation layers, futuristic heating components, thick gloves, hats, balaclavas, and extremely cold vapor boots (which Antarctic researchers affectionately call rabbit boots or The only necessary modification is an insulated oxygen mask, and maybe a heater to prevent the supercooled air from frostbite your lungs. As long as the oxygen is circulating, the suit doesn’t even need to be completely sealed, which is like: “your bag can’t be inflated, but oxygen is still circulating in it.” < / P > < p > this leads to an interesting thought experiment: if people don’t need a sealed spacesuit on Titan’s surface, they can breathe the air of the surrounding environment through an oxygen mask. At this time, what does Titan smell like? Although Titan is smaller than Saturn, it is one of the largest satellites in the solar system. Its diameter is 2600 km, which is about half of the diameter of the moon. However, it has a thick and fuzzy atmosphere. < / P > < p > based on the data from NASA’s Cassini and European Space Agency’s Huygens probes, we have a full understanding of Titan’s atmospheric composition, so we can boldly guess what the planet smells like. < / P > < p > the two main components in Titan’s atmosphere are nitrogen and methane, which have no smell. You may think that the unique smell of methane is actually another gas (methylmercaptan). Due to the safety point of view, methyl mercaptan is added to methane gas for people’s daily use. Methyl mercaptan has a special smell. It smells like rotten eggs. Its content can be detected by human nose. By adding this odorous chemical substance into methane and natural gas, we can quickly find and deal with potential dangerous leakage points. < / P > < p > so, is there any other odor in Titan’s atmosphere? The list of trace components in Titan’s atmosphere that have been measured or predicted by researchers include hydrogen (H2), carbon monoxide (CO), ethane (C2H6), ethylene (C2H4), acetylene (C2H2), hydrogen cyanide (HCN), ammonia (NH3), propargyne (c3h4), propargynitrile (c3hn), benzene (C6H6), methane cyanide (CH3CN), methylamine (CH3NH2). < / P > < p > some of these gases have no odor, but some of them still have special odor. Hydrogen, carbon monoxide and ethane have no smell at all. People may think that acetylene has a special smell, but in fact it is as tasteless as methane. Acetylene used in welding operations contains phosphine impurities, which will release a garlic smell. < / P > < p > Titan’s thick atmosphere (dark blue) extends hundreds of kilometers above the surface of Titan. This image is a pseudo color image taken by Cassini. Ethylene in Titan’s atmosphere is the simplest olefin (two carbon atoms are linked by double bonds), and is also a common plant hormone, which can affect fruit ripening and seed germination. In its pure form, it has a sweet and musky odor. Similarly, acetonitrile, which is used in many chemical and organic synthesis reactions, has a sweet, similar odor. In addition, there is propyne, also known as methylacetylene, which is used in welding and rocket fuel. < / P > < p > in addition, there is hydrogen cyanide, which has the taste of bitter almonds. In some spy movies, hydrogen cyanide is a killing tool with strong toxicity. The effect of hydrogen cyanide is very rapid. In the air with very low concentration of hydrogen cyanide (0.005mg / L), people only have headache, discomfort and arrhythmia for a short time; in the air with high concentration of hydrogen cyanide (0.1mg / L), people will die immediately. < / P > < p > the surface of Titan may not have a very attractive odor, but ammonia in the atmosphere is a strong pungent odor, which is usually used as fertilizer or as the main component of smelling salt, and can produce a particularly concentrated urine odor. < / P > < p > in addition, Titan also has methylamine. In the TV series breaking bad, the protagonist Walter white is the originator of methamphetamine. Although the smell of the substance in the play is not the focus, it has the smell of rotting fish. These chemicals are by-products of the decomposition of animal tissues, and some organisms generate energy through the process of methane generation. Benzene is a known carcinogen in crude oil and also exists in Titan’s atmosphere. Although it is carcinogenic, it has a sweet, aromatic, gasoline like smell, close to the smell of organic solvents. < / P > < p > in this artist’s illustration, Titan’s hydrocarbon ocean waves are pounding the beach, and these hydrocarbons help Titan form more complex molecules. There are some potential odors in Titan, including sweet, bitter, spicy, rotten fish odor, and some subtle odor. But keep in mind that Titan’s surface is very cold, which means that only small molecules interact weakly with each other to remain volatile at a sufficiently low boiling point (which makes them easy to turn into steam). Only these tiny molecules can penetrate through gas masks and reach the astronauts’ noses. < / P > < p > so far, we have listed that all odorants are solid on Titan’s surface, which means they are not volatile, with the exception of one compound: ethylene. The hydrocarbon has a freezing point of – 169 degrees Celsius, only slightly higher than the surface temperature of Titan. In some experiments, scientists have found that ethylene remains liquid at minus 183 degrees Celsius. The reason why the salt drops on the road in winter is to prevent the salt from freezing. So ethylene is the most volatile molecule on Titan’s surface, and it gives a sweet musky smell. < / P > < p > however, the story of Titan’s smell is not over, and we need to consider the sensitivity of the human nose. Human odor thresholds are real, and you can find them in a variety of compounds. So even if a substance is frozen to a solid, at least some molecules escape. If the human nose is sensitive enough to detect them, the brain records them as odors. < p > < p > in terms of odor threshold, three molecules are most prominent: hydrogen cyanide and benzene have the same odor threshold – 5 ppm (PPM), and methylamine has an odor threshold of – 0.0021 ppm. In contrast, it takes up to 270ppm to smell ethylene. It’s like mixing gasoline, almonds and dead fish. < / P > < p > finally, we must also take into account the ability of humans to perceive odors, which is called olfactory acuity, depending on age, smoking habits, gender and nasal allergies. In addition, there are some genetic factors at work, such as hydrogen cyanide, which was previously mentioned as unheard of. At the same time, how Titan’s smell is affected by how much each astronaut smells. < / P > < p > so, what is Titan’s odor? We believe that the most common answer for astronauts is: sweet, musky (ethylene), fishy (methylamine), bitter almond (hydrogen cyanide), gasoline (benzene). < / P > < p > recently, NASA has selected the “Dragonfly program” to launch a small rotorcraft to land on Titan’s surface in 2034, and then the aircraft will fly off Titan’s surface to explore other Saturn satellites in a wider range. Is the answer < / P > < p > accurate? The final answer will be revealed by the future NASA space program. Recently, NASA has chosen “Dragonfly project” to launch a small rotorcraft to land on Titan surface in 2034, and then the aircraft will fly off Titan surface to explore other Saturn satellites in a wider range. During its mission, Dragonfly will use its state-of-the-art equipment to directly detect molecules in Titan’s atmosphere and surface. (Ye Qingcheng)= https://ibmwl.com/category/global-tech/#content target=_ blank>Skip to content