Furrows are a concentric system of tectonic troughs, and are the oldest recognizable surface feature on Ganymede.
We analyzed the distribution of furrows utilizing Voyager and Galileo images and found that furrows over Ganymede’s surface are part of a global concentric circular structure. If this multi-ring structure is impact origin, this is the largest impact structure identified so far in the solar system.

Deviations of the shapes of the furrows from the concentricity are small everywhere, which implies that the relative location of the blocks of the dark terrains over the entire surface of Ganymede has not changed appreciably even during formation of the bright terrains. The estimate of the impactor size is difficult, but an 150km-radius impactor is consistent with the observed properties of furrows.

The furrow-forming impact should have significant effects on the satellite’s geological and internal evolution, which are expected to be confirmed by future explorations of Jupiter’s icy moons, such as the JUICE (Jupiter Icy moon Explorer) or Europa Clipper mission.

Naoyuki Hirata, Ryo Suetsugu, Keiji Ohtsuki

Comments: 35 pages 12 figures
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2205.05221 [astro-ph.EP] (or arXiv:2205.05221v1 [astro-ph.EP] for this version)

Journal reference: Icarus Volume 352, December 2020, 113941
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Submission history
From: Naoyuki Hirata [view email]
[v1] Wed, 11 May 2022 00:45:03 UTC (2,527 KB)