Naming of the Martian Landforms

Why in News?

A 3.5-billion-year-old crater on Mars will henceforth be known after M.S. Krishnan, the pioneering Indian geologist, proposed by Kerala-based researchers.

• Approved by – The International Astronomical Union (IAU).
• New names - Apart from ‘Krishnan,’ the IAU has also accepted several Kerala-based names for smaller landforms associated with the crater.
• These are ‘Valiamala,’ ‘Thumba,’ ‘Bekal,’ ‘Varkala’ and ‘Periyar’ for smaller craters and a vallis (valley).

General IAU Naming Rules

• The IAU adheres to several overarching principles for all planetary nomenclature.

• Clarity and Uniqueness - Names should be simple, clear, and unambiguous. Duplication of names across different bodies is discouraged.
• Scientific Need - Features are named only when they have special scientific interest and the name is useful to the scientific community for communication and mapping.
• Size Limits - Generally, official names are not given to features with the longest dimensions less than 100 meters.
• International Basis - Nomenclature should be international, with equitable selection of names from various ethnic groups, countries, and genders.
• No Political/Military/Religious Significance - Names with political, military, or religious significance are prohibited, except for political figures who lived before the 19^th century.
• No Living Persons - Features may only be named for persons deceased for at least three years, and generally only for those of high and enduring international standing.
• Informal Names - Mission teams often use informal names (nicknames) for small, temporary features (rocks, soil samples, etc.) for operational purposes, but the IAU does not officially recognize these.
• Specific Martian Naming Themes - For features that do meet the IAU criteria for official naming, specific themes are applied to different feature types on Mars:
• Large Craters (>60 km diameter)- Named after deceased scientists who have made foundational contributions, or science-fiction authors of high and enduring international standing.
• Small Craters - Named after small towns and villages of the world with populations of approximately 100,000 or less.
• Large Natural Features - Mons (mountains), Patera (shallow craters), Planitia (plains), Planum (plateaus), Vallis (valleys), etc.
• Themes vary, but often draw from classical albedo features on early maps, or are associated with existing major names (e.g., the name for a large structural feature might be linked to a nearby named crater).

Reference

The Hindu | Naming of Martian land forms