CNN News:MAVEN检测火星大气

At the moment, it's not possible to get someone to Mars and back alive. One of NASA's five active missions called MAVEN involves a satellite orbiting Mars that took more than ten months to get there from earth. Still, because NASA hopes to put someone on Mars one day, they're getting all the information they can from MAVEN and its $672 million mission.

现在，让人们登上火星，并活着回来，是不可能的。NASA现在执行的5个任务中，有一个叫做 MAVEN(美国国家航空航天局2011年火星探测计划 )，是一个卫星以火星为轨道转动，从地球到火星需要10个月的时间。但是，因为NASA希望将来能将宇航员送上火星，所以，他们在收集所能从MAVEN收到的信息，该项活动耗资6.72亿美元。

Thanks to the space probe MAVEN, we now have clues in the mystery of Mars' shift from a warmer, wetter environment to the cold, dry desert it is today.

由于MAVEEN的空间探测器，现在，我们已经掌握了火星的环境从温暖、湿润转变成现在寒冷、干旱沙漠的奥秘。

MAVEN has been exploring Mars' atmosphere since 2014. One of its main goals is to figure out how and why it got so thin. This low high pressure atmosphere is comprised mostly of carbon dioxide will prevent fresh water from being present, because it will boil at 10 degrees Celsius or 50 degrees Fahrenheit. On Earth, it boils at 212 degrees Fahrenheit.

MAVEN从2014年开始就一直在探测火星的大气。其主要目的之一就是查明火星的大气变得稀薄的途径以及方式。这种主要由二氧化碳组成的低高压氛围，将使现在不复存在淡水，因为淡水在那种低高压氛围内10摄氏度(50华摄氏度)就会沸腾。而在地球上，水的沸点是212华氏摄氏度。

And now, NASA scientists think they know the culprit -- solar winds. They observed a massive amount of ions and gases escaping during solar bursts like coronal mass ejections. Since the sun would have been incredibly active in its infancy, the prevalence and strength of these bursts could have had a tremendous influence in the evolution of the Martian environment and the thinning of the atmosphere.

现在NASA科学家们觉得自己知道了事情的罪魁祸首——太阳风。他们观察到在日冕物质抛射等太阳爆发活动中有大量的离子以及气体释放。因为太阳自开始阶段就异常活跃，这就导致这些爆炸活动的频率以及力度会对火星环境的变化以及大气变薄产生重大的影响。

Scientists also observed a unique type of aurora called the diffuse aurora in the planet's northern hemisphere. Auroras occur when particles collide with a planetary atmosphere along electromagnetic fields. They're not uncommon. In fact, they've been observed above all planets with a substantial atmosphere, even some moons.

科学家们也观察了该星球北半球的一种独特类型的极光称为分散极光。当粒子在磁场与行星雾团相撞时，就会产生极光。然而，极光很常见。实际上，所有的空气的行星，甚至一些卫星上都可以看到此种现象。

But the aurora seen on Mars was at the lowest altitude observed on any planet. The unique characteristics of this aurora versus those observed on Earth may be determined by the very different magnetic field configurations of the two planets.

但是，火星上看到的极光高度是最低的。这种极光的独特特征以及在地球上所观察的这样现象可能是有两个星球不同的磁场配置决定的。

As NASA gears up to send astronauts to Mars in the 2030s, they hope to gain further insights into the Red Planet's past, so we can better prepare ourselves for these future missions.

因为NASA准备在21世纪30年代将宇航员送到红星，因此，他们希望能够深入了解火星的历史，这样的话，我们就能够为未来的这些任务做好准备。