演讲人：Justin

Morning everyone，lets have a chat about is it possible for humans to live on Mars. 

Mars is about half the size of Earth in diameter and it has a much finer atmosphere, its only 1% of Earth’s. The atmospheric configuration is also greatly different, primarily carbon dioxide-based, while Earth is rich in nitrogen and oxygen. The atmosphere has of course evolved since, because mars is smaller than earth, its further away from the sun so mars is faced with the cold black icy void, as it refrigerated the iron nickel core solidified, before the planet can create the building blocks of life. Mars rusted before any skeletons could bedeck its deserts. 

Like the lapis lazuli gem it resembles, the blue, cloud-enveloped sky we see when we look up. earth was like this about 4.5 billion years ago. As the time rolled on carbon dioxide blanketed the sky, humans are increasing the emissions by burning fossil fuels, cutting down trees, and by over hunting predators, by over hunting this will gradually increase herbivores, increasing the amount of plants disappearing every year, finally decreasing the volume of carbon dioxide absorbed adding more greenhouse effect to those natural occurring, thus increasing the overall temperature of the planet.

So, by turning the telescopes to the vast solar system scientists discovered that only mars is the most suitable semi habitable planet in range, first the moon is the closest but it does not have an atmosphere and the surface temperature can vary from 120 Celsius at lunar day time to -253 Celsius at night, which is impossible to live on. Moving on, Jupiter, Saturn, Uranus and Neptune are gas giants they don’t even have a solid core, Mercury and Neptune, those two are ether to close to the sun or to far, by the looks of it Mars seams to be the only choice.

The two key factors for basic human living is food and water, water is actually the most easy of two, the poles of the planet has marks of liquid. Scientists are experimenting which types of plants can survive in Martian soil.

In the past cross planetary migration only happened in comics and science fiction movies, but the dream is slowly coming true, with the continues hard work of  scientists, cross planetary migration will soon happen.

Thanks for listening.

早上好，让我们聊一聊人类是否有可能生活在火星上。

火星的直径大约是地球的一半，大气层也要细得多，只有地球的1%。大气结构也大不相同，主要是二氧化碳，而地球富含氮和氧。当然，由于火星比地球小，离太阳更远，因此火星在冷却凝固的铁镍核之前，面临着寒冷的黑色冰冻空洞，因此大气层也在进化，火星在任何骨骼覆盖其沙漠之前就已经生锈了。

当我们抬头时，我们看到的是蓝色的、云层笼罩的天空。大约45亿年前，地球也是这样的。而随着时间的推移，二氧化碳覆盖了天空，人类燃烧化石燃料、砍伐树木、过度狩猎捕食者从而增加排放，而过度狩猎将逐渐增加食草动物，造成每年植物数量减少，最终给自然产生的二氧化碳增加更多的温室效应，提高地球的整体温度。

因此，通过将望远镜转向广阔的太阳系，科学家们发现，只有火星是范围内最适合半宜居的行星，首先，月球离太阳最近，但它没有大气层，表面温度从月球白天的120摄氏度到晚上的-253摄氏度不等，这是不可能生存的。继续看，木星、土星、天王星和海王星都是气态巨星，它们甚至没有固体核心，水星和海王星，这两颗行星是接近太阳或远离太阳的以太，从外观上看，火星是唯一的选择。

人类基本生活的两个关键因素是食物和水，水实际上是最容易的两个因素，地球的两极有液体的痕迹。科学家们正在试验哪些类型的植物可以在火星土壤中存活。

在过去，跨行星迁徙只发生在漫画和科幻电影中，但梦想正在慢慢实现，随着科学家们的持续努力，跨行星迁移很快就会发生。

感谢！