Depth data from Kurt Fisher database
- Westfall, 2000: 2.6 km
- Viscardy, 1985: 2.1 km
- Protagoras (ca. 490– 420 BC) was a pre-Socratic Greek philosopher and is numbered as one of the sophists by Plato. In his dialogue Protagoras, Plato credits him with having invented the role of the professional sophist or teacher of virtue.
- The crater now officially known as Protagoras was once called Ward by William Radcliff Birt.
- Protagoras Xi (hill east of Protagoras, at 56°45' North/ 15° East, see Chart 4 in the Times Atlas of the Moon). This hill seems to be known as Protagoras Epsilon on SLC map C1 (System of Lunar Craters, 1966).
"Ward": MAPPING AND NAMING THE MOON, Ewen A. Whitaker (page 221, Appendix J).