Chandrayaan-4 to Land on Mons Mouton Near Moon South Pole

Chandrayaan-4 to Land on Mons Mouton Near Moon South Pole

Why in News? 

India’s upcoming Chandrayaan-4 mission is planned to land near Mons Mouton (MM-4), a mountainous region close to the Moon’s south pole, as the safest and most scientifically valuable site for the country’s first lunar sample-return mission. 

• Scientists from ISRO identified this landing zone using high-resolution imagery from the Chandrayaan-2 orbiter, aiming to collect lunar rocks and soil and bring them back to Earth for study.

What is Mons Mouton (MM-4)?

• About: Mons Mouton is a significant lunar mountain (mons) located near the Moon’s south polar region on the near side, between the large Nobile and Malapert craters. It is officially recognized by the International Astronomical Union (IAU) as a named lunar feature, with Feature ID 16070 in the Gazetteer of Planetary Nomenclature.

• Name Origin: The name “Mons Mouton” honors Melba Roy Mouton (1929–1990), an American NASA mathematician and computer programmer who led early spacecraft trajectory analyses during the formative years of U.S. space exploration. 

• Geographic Coordinates: Mons Mouton lies at approximately 84.60° S latitude and 31.00° E longitude, placing it within 6° of the lunar south pole, where extreme lighting conditions and rugged terrain dominate. 

• Physical Characteristics: Mons Mouton rises about 6 km above the surrounding lunar surface, roughly equivalent in height to Denali, the tallest mountain in North America.

• Its summit region is relatively flat-topped and plateau-like, distinguishing it from more sharply peaked lunar mountains.

• • • The mountain spans around 130 km in diameter, making it one of the largest named features near the lunar polar region.

• Geological Formation: Mons Mouton is believed to be part of the South Pole–Aitken Basin rim’s complex geology—the basin being one of the oldest, largest, and deepest impact structures in the Solar System. Its terrain has been shaped over billions of years by repeated impacts, leaving an ancient surface with a mixture of large and small craters.

Why MM-4 was Chosen for Landing?

• Hazard Assessment and Terrain Safety: MM-4 was identified for its low hazard percentage. The area has fewer large craters, boulders, and steep slopes that could jeopardize a soft landing. Terrain modeling found that the 1 km × 1 km zone around MM-4 contains the highest number of hazard-free grids (24 m × 24 m) compared to other candidate sites, significantly reducing the risk during powered descent and touchdown.
• Gentle Slopes and Landing Stability: The mean slope at the MM-4 site is around 5°, which is considered gentle relative to many other regions near the lunar south pole that feature steep inclines and complex topography. Gentle slopes increase the likelihood of a stable lander touchdown, minimize the need for aggressive horizontal corrections.
• Favorable Illumination Conditions: MM-4 was chosen because it receives adequate sunlight during portions of the lunar day, which is critical for powering the lander’s solar panels and maintaining operational temperatures. MM-4’s illumination profile provides a balance between scientific interest and operational feasibility.
• Scientific Value of the Surrounding Region: The Mons Mouton area, including MM-4, lies close to permanently shadowed regions (PSRs) that are believed to trap water-ice and volatiles. Access to materials near these PSRs enhances the mission’s scientific potential, as lunar samples could contain clues about water distribution, volatile compounds.