小行星與天體物理環境交互作用的影響

小行星與天體物理環境交互作用的影響


Public Seminar of Research Postgraduate Programmes Student:- The Effects of Interaction between Asteroids and Astrophysical Environment 

The first interstellar object, ’Oumuamua, was discovered in 2017, which is in an excited rotation around non-principal axis. It is now heading away from solar system and cannot be observed by astronomical telescopes any longer due to its rapid movement and low brightness. During its travel in interstellar space, its interaction with interstellar environment will occur. The physical process of interaction is dominated by collision between the asteroid and interstellar medium such as gas and dust.

Since gas and dust possess momentum and energy. Each of these interactions leads to changes in the modification of surface and its angular momentum. If considered for only a short period of time, these changes are very small, but over longer periods of time, these changes may integrate to significant changes in its motion.

In addition, although interaction between asteroids and interstellar starlight radiation makes small changes during a short timescale, artificial laser can cause a huge deformation of asteroids’ surface. Powerful laser can heat up the asteroids and raise the temperature up to the critical temperature of evaporation, producing mass ejection and providing a force on the asteroids. Directed energy of laser is expected to defense the Earth from impacts of near Earth objects by evaporating them or changing their orbits. Therefore, it is meaningful to fully understand the physical process of the interaction between asteroids and laser radiation.
 
時間:2019.05.03(五) 16:00
地點:香港大學 莊月明物理樓522室
講者:Wenhan ZHOU(香港大學)
語言:英語

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此活動由香港大學物理系主辦。