SEIS:监听火星地震
影像来源与版权:NASA, JPL-Caltech, Mars Insight

说明:如果把你的耳朵放在火星上,你会听到什么?为了发现和探测未知的火星内部,美国航天局的洞察号着陆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,在监听到着陆器自身发出的风和运动之后,SEIS记录了一个前所未有的事件,与预期发生的火星地震相符。该事件可以在视频中看到。尽管人们认为火星并不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可以听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,如果存在的话。在这幅上周拍摄的影像中,SEIS静静地安放在火星表面,吸收一些太阳光,而轻云在地平线上空可见。
翻译:北京天文馆

SEIS: Listening for Marsquakes
Image Credit & Copyright: 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 YouTube video. 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.
Astronomy Picture of the Day 06/04/2019