报告地点:ZOOM ID:828 7414 0755
报告时间:星期五,2022-12-09 15:00 -16:30
报告人:Taichi Kawamura (Institut de physique du globe de Paris)
报告题目:Martian Seismology as seen by InSight
NASA InSight mission landed on Mars on Nov. 26th 2018 andopened a new frontier of planetary seismology. The seismometer, which is one ofthe main scientific payload of the mission, has been deployed on the ground inearly 2019 and carried out almost continuous monitoring of Martian seismicity.During more than 1350 martian days of observation, the seismometer has detectedmore than 1300 marsquakes including the M4.7 giant marsquake that was detectedjust before the mission entered power cycling mode due to a severe power issue.The two solar panels that are used to power the spacecraft and the instrumenthave steadily accumulating Martian dust and the power generation has degradedsignificantly. The mission is now approaching the end but we have alreadyaccomplished many of the scientific objectives of the mission. In thispresentation, I will describe some of the key observations of InSight anddiscuss the implications to Mars Science. First, I will discuss how we obtainedthe first internal structure model from the crust, mantle down to the core.Using some classical approach of seismology, we succeeded for the first time indefining the 1D structure of Mars. Secondly, I will describe the impact eventsthat were detected by the seismometer and with the imagery from the orbit. Suchobservation which provides us with independent contraints on the location willbe extremely helpful to further investigate the shallow structure of Mars.Finally, I will describe the largest marsquake detected so far, which showsmany features that was not visble with other smaller marsquakes. I willconclude by summarizing the achievement of the mission by comparing this withour mission objectives.