Atlas of Martian Geography: MC-5

Atlas of Martian Geography: MC-5 is the fifth sectional chart in the ongoing Atlas of Martian Geography series by Thomas Gangale, JSD, serving as the visual companion to the Encyclopedia of Martian Geography. MC-5, titled Ismenius Lacus, covers the Ismenius Lacus quadrangle region of Mars (approximately 0°–30°N latitude, 270°–360°E / 0°–90°W longitude). This high-resolution map is rendered using USGS Mars Global Surveyor Mars Orbiter Laser Altimeter (MGS MOLA) global color shaded relief data at ~463 m/pixel resolution, providing detailed visualization of the planet's mid-northern latitudes.Key scholarly features include: Precise overlays of revived classical albedo nomenclature from 19th- and early 20th-century telescopic observations (e.g., by Giovanni Schiaparelli, Percival Lowell, Eugène Antoniadi, and contemporaries), integrating dozens of historical names not retained in the modern IAU Gazetteer. Cross-references to official IAU-approved toponyms, linking classical features such as Ismenius Lacus, Niliacus Lacus extensions, Protonilus Mensae, and adjacent regions of Arabia Terra, Deuteronilus Mensae, and the northern lowlands' transition zones. Annotations on etymology (drawing from classical Greek and Latin sources), observational history, and how early albedo contrasts—once interpreted as seas, lakes, or canal networks—align with or reinterpret modern volcanic, tectonic, and periglacial landforms revealed by spacecraft data. Visual emphasis on major topographic elements: the transition from the heavily cratered ancient highlands of Arabia Terra in the south to the smoother northern plains, fretted terrain along the dichotomy boundary, possible outflow channel remnants, and impact features such as Lyot Crater in the northern portion. MC-5 continues the project's goal of fusing historical astronomical heritage with contemporary areographic precision, enriching place-name context without altering official IAU nomenclature. The chart supports research in planetary science, astrogeology, historical cartography, and future Mars exploration planning.This chart is distributed open-access via the Zenodo record for Volume 1 (alongside the encyclopedia text, MC-1 through MC-4, and subsequent additions). Citation recommended: Gangale, T. (2026). Atlas of Martian Geography: MC-5.