Chandrayaan-3 successfully launched: Why ISRO scientists want to explore Moon's South Pole?

On Friday (July 14), Chandrayaan-3, the follow-up mission to Chandrayaan-2, was successfully launched at 2.35 pm from the Satish Dhawan Space Center (SDSC) in Sriharikota. Chandrayaan-2 faced a setback in 2019 when its lander and rover were unable to execute a soft-landing on the Moon.

According to officials from the Indian Space Research Organisation (ISRO), Chandrayaan-3 is expected to reach the lunar orbit approximately a month after launch. The mission's lander, Vikram, and rover, Pragyaan, are anticipated to land near the south pole of the Moon on August 23. This landing site is similar to that of Chandrayaan-2, with a latitude of 70 degrees. If successful, Chandrayaan-3 will become the world's first mission to achieve a soft-landing near the lunar south pole.

Historically, all previous spacecraft that landed on the Moon did so in the equatorial region, a few degrees north or south of the lunar equator. The farthest any spacecraft has ventured from the equator was NASA's Surveyor 7, which landed near 40 degrees south latitude on January 10, 1968.

The reason for the preference of equatorial landings is the ease and safety they offer. The terrain and temperature in the equatorial region are more favorable for sustained operation of instruments. The surface is relatively even, with fewer steep slopes, hills, or craters. Abundant sunlight, especially on the side facing the Earth, ensures a regular energy supply for solar-powered instruments.

The polar regions of the Moon, on the other hand, present a challenging and vastly different terrain. Many areas are in complete darkness, with no sunlight reaching them, and temperatures can drop below -230 degrees Celsius. Lack of sunlight and extreme cold make it difficult to operate instruments. Moreover, the presence of large craters of various sizes further complicates the situation.

Despite the challenging environment, scientists are keen to explore the lunar south pole due to its potential significance. Orbiter missions have indicated the presence of substantial amounts of ice molecules in deep craters within this region. India's Chandrayaan-1 mission in 2008 provided evidence of water on the lunar surface through its onboard instruments. The extremely low temperatures in the polar regions mean that any trapped substances would remain preserved, potentially offering valuable insights into the early Solar System.

In certain parts of the lunar polar regions, there is no sunlight due to the Moon's unique axis tilt. Unlike Earth, which has a tilt of 23.5 degrees, the Moon's axis tilts only 1.5 degrees. This results in the floors of several craters near the lunar poles being permanently shadowed, referred to as Permanently Shadowed Regions (PSRs). NASA's Lunar Reconnaissance Orbiter (LRO) has indicated that these cold surfaces could sustain water for extended periods, providing opportunities for scientific investigation.

The launch of Chandrayaan-3 marks another significant step in India's space exploration endeavors, with hopes for valuable discoveries and advancements in our understanding of the Moon's south pole.

Read more: Explained: Why did Chandrayaan 2 fail? Can these mistakes be repeated in ISRO’s Chandrayaan 3?