Murchison is a lunar impact crater on the north edge of the Sinus Medii. It was named in honour of the geologist Sir Roderick Murchison. It shares a section of rim with the crater Pallas. To the southeast on the mare is the circular crater Chladni, and to the northeast is Ukert. Farther to the east is the prominent Triesnecker. Murchison lies astride the lunar zenith line, i.e. the starting longitude of the selenographic coordinate system. The wall of Murchison is heavily worn and has completely disappeared in a wide gap to the southeast. The rim is most intact along the northeast part of the crater, but even there it is indented and irregular. Only a ridge remains of the rim shared by Pallas and Murchison, with gaps to the north and south. A low ridge from the east wall runs south to join the rim of Chladni. The crater floor has been flooded with lava and joins the Sinus Medii through the wide gap in the southeast wall. Satellite craters By convention, these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Murchison. References External links Murchison at The Moon Wiki Intricate Young Ejecta Blanket in Ancient Murchison - Rima Bode, also includes Murchison Crater Impact craters on the Moon