Context: India’s ISRO is launching Chandrayaan-3 mission to moon. However, along with ISRO other space faring nations are also planning mission towards moon. This article explores the reasons behind the same.

Moon
- Moon is the only satellite of Earth.
- It is devoid of atmosphere and rotates.
- Moon revolves around the Earth in around the same time as Earth rotates on its axis.
- Tidal locking is a phenomenon by which a body has the same rotational period as its orbital period around a partner. Since, moon rotates the Earth at the same time as it takes to orbit Earth. Thus, we can see only one side of the moon.
Recent missions planned or executed for Moon
- Chandrayaan-3 by India’s ISRO which is equipped with lander and rover.
- Luna 25: Russia’s moon lander mission scheduled in 2023.
- Artemis Program of NASA (USA): Aims to send a manned mission to Moon by 2025.
- China plans to send a manned mission to Moon by 2030.
- SLIM Mission: It is small scale exploration mission by JAXA (Japan) designed for pinpoint landings on the Moon’s surface, reduction in size and weight of equipment used in Moon landings and investigation into Moon’s origins.
- Ispace: It is a Japanese startup aiming to have a lander on Moon in 2023.
- Private American aerospace companies Intuitive Machines and Astrobotic Technology each aim to place a lander on moon.
- India has ratified the Artemis Accords which establishes a framework for cooperation in civil exploration and peaceful use of Moon, Mars and other astronomical objects.
Reasons behind increased focus on Moon
- Moon is being seen as a vital stepping-stone for interplanetary exploration.
- Moon has presence of rare minerals and elements including titanium and helium-3 that could be used to build nuclear fusion plants.
- Moon has presence of frozen water which can be harnessed for sustaining a population and agriculture.
- There is a race among nations to figure out how to get these precious resources and transport them to Earth.
Recent findings about Moon
Characteristics of far side of moon:
- Far side of the moon has a dramatically different landscape as compared to the face of moon visible from Earth. Far side has a thicker crust by almost 20 km.
- The far side of the moon is also more densely pockmarked, with millions of more asteroids and comets having crashed into this half.
- Far side of moon has almost no characteristic dark spots which are less reflective volcanic basalt plains.
Water on Moon
- Chandrayan-1 (India’s first lunar mission) carried two instruments provided by NASA for surveying the poles of moon for possible traces of water ice.
- The instruments were (i) Moon Mineralogical Mapper – An infrared spectrometer & (ii) MiniSAR – Miniature Synthetic Aperture Radar.
- These instruments gave a definitive proof of presence of water ice in more than 40 craters on the poles of moon indicating potential for life, for research stations or settlements, perhaps even crops.
- Scientists believe that water is concentrated in the craters at the poles of moon because they don’t receive any sunlight. On other parts of moon, a combination of low pressure and daytime temperatures of 120 degree celsius vaporises water.
- However, in 2020 NASA’s SOFIA Observatory found the first evidence of water on moon in a sunlit spot, indicating presence of water on the Moon was widely distributed.
Moon’s soil
- Lunar soil, also known as regolith, contains a number of familiar elements such as iron, silicon, potassium, manganese and magnesium. However, it does not contain organic matter such as microbes and insects.
- Lunar soil is hydrophobic i.e., it repels rather than absorbs water.
- Lunar soil has been exposed to extremely unhealthy amounts of solar radiation.
- Last year, scientists on Earth succesfully grew plants in lunar soil brought back to Earth by NASA’s Apollo missions in the 1970s. However, scientists found that plants in lunar soil were growing slower, had stunted roots and leaves and developed red spots. This was due to much higher exposure to salt or heavy metals. However, drought tolerant plants fared better in lunar soil.