My Little Pony: My Little Pony The Martian

"Randall," Venkat said straight to the point, "What's the weather like on Mars recently? Didn't you say before that the dust was coming back, but Watney told me that the weather today is still the same as the first batch of photos taken by the Viking probe. The photos are all blue - those are the result of a white balance mistake."

"It's the clouds," Randall Carter answered. He handed Venkat some recent satellite images taken by the Mars High Orbiting Orbiter, "At this time of year we usually see a lot of cirrus clouds - high-altitude clouds made of tiny water ice crystals - when Mars arrives. Aphelion. Theoretically this point should have been a few months ago, but now they are back and growing."

"What caused it?" asked Venkat. "Is it nucleation caused by dust particles?"

"This is a possible reason," Carter said cautiously, "but more importantly, the higher-than-normal temperatures in the area between the equator and 30 degrees north and south latitude may have caused a large amount of water-ice mixture below the surface to sublime into the Atmosphere. The more moisture there is in the atmosphere, the more clouds there will be. When ice crystals form in the air, dust particles that serve as nucleation points will be trapped in the ice crystals, and the final effect is to remove dust particles from the air." He pointed to the bright blue strip clearly visible in the upper atmosphere at the edge of Mars in a photo, "If there were no dust in the air, all that would be left would be ordinary gaseous molecules, which would form the same thing as us." The Rayleigh scattering effect is the same effect seen every day on Earth. This would explain what Watney saw - blue sky and white clouds."

"Okay, it doesn't sound harmful." Venkat asked again, "How long will this phenomenon last?"

"My guess is that it's about a month away," Carter replied, "maybe less. Then Mars will be close to the sun again, and these cirrus clouds will usually sublimate again. The water vapor will eventually be broken down into hydrogen and oxygen by ultraviolet light. If it escapes from the atmosphere, it will either be circulated to the lower atmosphere and condense back to the surface." He pulled out another printed material and added, "But the problem is, I don't think this trend is harmless to humans and animals."

Venkat took the data and looked at it, "Randall, I'm a physicist, not a meteorologist." He said, "I can see these temperature and air pressure data, but I don't have the background knowledge required to interpret them. .”

"It's really too high." Randall explained, "It's summer in the northern hemisphere of Mars, and its orbit has just begun to approach the sun. At this time, all the carbon dioxide in the atmosphere of the southern hemisphere should condense, causing the air pressure to drop. However, in fact That’s not the case at all.”

"why?"

"The temperature is too high. Under normal atmospheric pressure conditions on Mars, the condensation temperature of carbon dioxide is around minus 123 degrees Celsius," Randall continued to explain. "Under normal circumstances, the lowest temperature in the southern hemisphere in winter will reach or even lower than minus degrees Celsius. We can see the corresponding effect of the cyclical expansion and contraction of the Martian ice sheet every year in the photos taken in different seasons. The part of the ice sheet that expands and contracts is almost entirely composed of carbon dioxide. . But now the temperature in the polar regions will only drop below the condensation point briefly, and the area covered each time is not very large. Therefore, the atmosphere of Mars has not changed at all."

"Okay," Venkat replied, "but I still don't understand why this would affect Watney and the ponies."

"Actually, I can't see any specific impact," Randall admitted, "but I can guarantee that it will have an impact on them. Judging from the current situation, the atmosphere is thicker than normal, plus Cloud cover - did I just mention it's still growing? Mark will soon be able to see the clouds. Anyway, although not as strong as carbon dioxide or methane, water vapor is a greenhouse effect. gas. So the heat absorbed during the day is released more slowly at night. Mars is about to experience its first high-temperature heat wave in history."

"How high is the high temperature you are talking about?" Venkat asked.

"Next, the peak temperature in residential areas will reach double digits above zero degrees Celsius, and will last for at least two weeks." Randall replied, "The temperature at night is still around minus 40 degrees, but during the day the air conditioner The extravehicular components will shut down due to overheating. The extravehicular components need to maintain extremely cold temperatures to condense and separate specific components in the atmosphere..."

"Of course I know this. I'm not ignorant to that extent." Venkat was unhappy, "But the equipment in the cabin can still work normally, and the oxygen synthesis will not be affected."

"I'm not really worried about whether the equipment in the residential area will be affected," Randall continued. "I'm worried about what the next weather pattern will be based on this trend. We have never observed this on Mars before. This kind of weather phenomenon is almost global this time. The day and night temperatures are 20 degrees Celsius higher than normal globally. The energy contained in the atmosphere is so huge, and such powerful energy must have a way out in the end. .”

"Then try to find out." Venkat replied.

"I've got a guess," Randall said, "but you won't be happy to hear it."

"At least it's better than not guessing anything. Tell me quickly."

"Okay, okay. On Earth, rising temperatures mean more giant storms—hurricanes or typhoons like those on the East Coast, which are large weather systems. Their function is to transfer heat energy from the surface and lower atmosphere to The upper atmosphere, and then radiates out into space. However, there will be no rainfall on Mars. The closest phenomenon to precipitation on Mars is the occasional dry ice snowfall at the poles. Therefore, there is only one way to release energy. : A giant dust storm covering the entire planet.”

"When?" Venkat became nervous, "Randall, this matter is life-threatening. We will soon send six people on an arduous journey that will only rely on solar energy for thousands of kilometers. And out of Due to logistical reasons, we can't let them set off right away. There's no time to waste, and I need answers right away."

"So this is the situation?" Teddy asked after listening.

"That's it," Venkat replied, "I have also considered recruiting a group of people to form an emergency team to send the refugees on the road now, but I still recommend not to take this road."

"Analyze the pros and cons for me." Teddy subconsciously rearranged the manuscripts that had been neatly aligned with the blotting paper on the table.

"Good. The advantage is: the earlier they set off, the more room for maneuver they have to reach Schiaparelli before solar day 551. This can alleviate the time pressure to a certain extent. But the advantage is only this. The downside: They also need to pack more food into their already severely overloaded car. If they were to encounter, say, a global dust storm like the one in 2018, rather than leaving them stranded in Arabia It’s a ghost place in the middle of the platform with no villages or shops. It’s better to let them stay in the residential area and forget about missing Hermes. If the global dust storm produces strong winds like the Sol 6 storm, or an outbreak like the Sol 247 In the event of lightning activity, the cabin and cave are much stronger and safer.”

"Does that mean that as long as we find a dust storm forming on Solar Day 451, we will let them stay in Asidaria?" Teddy asked.

"Not necessarily." Venkat explained, "Don't forget, we knew from the beginning of this plan that when they drove to Schiaparelli, the dust storm season on Mars would also start at the same time. Originally we considered As for the slight risk of being trapped in a dust storm, it is just a hypothesis: the possibility is so small that it can be ignored. A global dust storm that is strong enough to completely cover the sky is a small probability that can only be encountered once in a generation. event. In some years, there were not even any global dust storms on Mars, not even super weak ones. But even so, setting off early cannot significantly reduce the risks encountered during the journey, and it is not worth spending a lot of energy on it. Overcome various logistical issues.”

"Okay then," Teddy concluded, "Xiaowen, you can make your own decision on this matter, but if someone from the Meteorology Department comes up with a clearer and more conclusive conclusion, please be sure to inform me as soon as possible."

"You are seventh on the notification list." Venkat replied seriously.