One hypothesis for such characteristics is that the impactor which formed Tyre penetrated through an icy crust into a less brittle layer. The crater Callanish, while similar in size to Tyre, shows a much more subdued ring structure with a central zone of relaxed rugged topography. While Pwyll, Cilix, and Mannann'an also display shallow crater depths for their size, they more closely resemble similar sized craters on two neighboring moons of Jupiter, Ganymede and Callisto. Perhaps the impactor did not punch through the upper crust during these events. This might have been the case if the impacting body was smaller or weaker than in the case of Tyre or if the crust was thinner at the location of Tyre during the impact event.
North is to the top of the picture.
The sun illuminates the surfaces from the right, except for Tyre, where the sun illuminates the surface from the left. The horizontal and vertical grey lines in the Tyre and Callanish mosaics indicate gaps in the data received for the respective image. The ASU Planetary Geology Group is under the direction of Dr. Ronald Greeley.