Gertrude is the largest known crater on Uranus's moon Titania. It is about 326 km across, 1/5 of Titania's diameter.[a] It is named after the mother of Hamlet in William Shakespeare's play Hamlet. Features on Titania are named after female Shakespearean characters.
The crater rim of Gertrude is elevated by 2 km over the crater floor. In the center of the crater there is a large dome, which resulted from the uplift of the surface immediately after the impact. The dome has the diameter of about 150 km and is 2–3 km high. The rim and dome are low for crater with such a large diameter indicating that the relief has relaxed since the impact. The surface of the dome has only few superimposed smaller craters, which means that it was modified later.
- USGS/IAU (October 1, 2006). "Gertrude on Titania". Gazetteer of Planetary Nomenclature. USGS Astrogeology. Retrieved 2012-03-28.
- Moore, Jeffrey M.; Schenk, Paul M.; Bruesch, Lindsey S.; Asphaug, Erik; McKinnon, William B. (October 2004). "Large impact features on middle-sized icy satellites" (PDF). Icarus. 171 (2): 421–443. Bibcode:2004Icar..171..421M. doi:10.1016/j.icarus.2004.05.009.
- Gertrude peeks over the terminator at the Planetary Society