2019 June 4

NASA, JPL-Caltech, Mars Insight

说明:如果你把耳朵放在火星上,你会听到什么?为了找到答案,探索未知的火星内部,美国宇航局的洞察号探测器在去年年底部署了火星内部结构地震实验仪(SEIS),这是一种灵敏的地震仪,可以探测到“火震”。4月初,在听到火星风和洞察号自身发出的声音之后,SEIS记录了一个前所未有的事件,该事件与“火震”(marsquake)的预期相符。这个视频可以在该网页上看到。尽管火星不像地球一样有构造板块,但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冷却时出现的,并且还在继续冷却。如果有足够强的“火震”发生,SEIS可以听到它们从火星内部的大型结构反射出来的隆隆声,就像液体核心一样,如果存在的话。 图为上周,SEIS安静地坐落在火星表面,接收太阳,同时在地平线上可以看到轻云。SEIS就能听到它们的轰隆声从火星内部的大型结构反射到火星上,就像液体内核一样,如果“火震”存在的话。上周拍摄的照片中,SEIS静静地坐在火星表面,接收阳光,同时在地平线上可以看到轻云。

SEIS: Listening for Marsquakes
Image Credit:
NASA, JPL-Caltech, Mars Insight

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 seismometer that can detect marsquakes. In early April, after hearing the wind and motions initiated by the lander itself, SEIS recorded an unprecedented event that matches what was expected for a marsquake. This event can be heard on this Web page. Although Mars is not thought to have tectonic plates like the Earth, numerous faults are visible on the Martian surface which likely occurred as the hot interior of Mars cooled — and continues to cool. Were strong enough marsquakes to occur, SEIS could hear their rumbles reflected from large structures internal to Mars, like a liquid core, if one exists. Pictured last week, SEIS sits quietly on the Martian surface, taking in some Sun while light clouds are visible over the horizon.