Dynamics of material ejected from the Hatmehit depression and landslides on comet 67P/Churyumov–Gerasimenko. (December 2021)

• Record Type: Journal Article
• Authors: Czechowski, Leszek; Kossacki, Konrad J.
• Is Part Of: Planetary and space science. Volume 209(2021)
• Publication Date: 2021-12
• Subjects: Comets -- Nucleus -- Geological processes -- Celestial mechanics; Space sciences -- Periodicals; Atmosphere, Upper -- Periodicals; Sciences spatiales -- Périodiques; Haute atmosphère -- Périodiques; 523
• DOI: 10.1016/j.pss.2021.105358
• Languages: English
• ISSNs: 0032-0633

Abstract

Abstract: In this work we investigate trajectories and regions of deposition of material ejected from depression Hatmehit on comet 67P/Churyumov–Gerasimenko. This depression, located on the lobe Head, could be a result of endogenic, possibly still ongoing, activity. We calculated trajectories of the ejecta with different initial velocities and we determined regions of their deposition. The gravitational field of comet 67P/CG is complex and its equipotential surfaces are dramatically different than its physical surface. Ejecta with the initial velocity ∼0.3 ​m ​s −1 are deposited close to the starting points. For ∼0.6 ​m s −1 a few regions of deposition are indicated. They cover significant areas but in the form of limited belt. These results are confirmed by observation. For ∼0.7 ​m ​s −1 ejected material is more dispersed and deposits in large area, e.g., in the Imhotep region or even near Hatmehit after a comet lap. We also estimated the role of some non-gravitational forces. Graphical abstract: Image 1 Highlights: The endogenic activity in region Hatmehit leads to formation of slow ejecta. Ejecta with velocity ∼ . 0. 3 ​m ​s −1 land close to the starting point. For 0.5 - 0. 6 ​m ​s −1 ejecta could land far but still in the limited belt. The above result is consistent with some observations. Ejecta with velocity ∼0. 7 ​m ​s −1 may be deposited in the Imhotep region.