Astronomy Picture of the Day——SEIS：监听火星地震
SEIS: Listening for Marsquakes
Image Credit: NASA, JPL-Caltech, MarsInsight
Explanation: If you put your ear to Mars,what would you hear? To find out, and to explore the unknown interior of Mars,NASA's Insight Lander deployed SEIS late last year, a sensitive seismometerthat can detect marsquakes. In early April, after hearing the wind and motionsinitiated by the lander itself, SEIS recorded an unprecedented event thatmatches what was expected for a marsquake. This event can be heard on thisYouTube video. Although Mars is not thought to have tectonic plates like theEarth, numerous faults are visible on the Martian surface which likely occurredas the hot interior of Mars cooled -- and continues to cool. Were strong enoughmarsquakes to occur, SEIS could hear their rumbles reflected from largestructures internal to Mars, like a liquid core, if one exists. Pictured lastweek, SEIS sits quietly on the Martian surface, taking in some Sun while lightclouds are visible over the horizon.
SEIS：监听火星地震
如果把耳朵贴在火星上，你会听到什么？为了发现和探知火星内部的未知结构，NASA的洞察号探测器在去年年底部署了SEIS，它是一台能探测到火星地震的灵敏地震仪。四月初，在一直监听着陆器周围的风声和它自己的震动之后，SEIS终于记录到一个前所未有的事件，与预期发生的火星地震相符。该事件的视频可以在YouTube上看到。尽管人们并不认为火星像地球那样具有地壳板块，但是在火星表面可以看到许多断层，这些断层很可能是在火星炽热的内部结构发生冷却时形成的，并且还在继续冷却。如果有足够强烈的火星地震发生，SEIS就可以探测到它们从火星内部的庞大结构反射到火星表面的隆隆声，就像一个液态核，如果它存在的话。在这幅于上周拍摄的图像中，SEIS静静地安放在火星表面上，晒着太阳，而浮云在地平线上空可见。
参考文献：
https://apod.nasa.gov/apod/image/1906/SeismometerClouds_Insight_1021.jpg
近期文章：
Astronomy Picture of the Day——哈勃望远镜拍摄的斯蒂芬五重星系