Chandrayaan-3’s landing, the experiments: lunar quakes and water-ice on Moon

24 Aug 2023 4 mins Download PDF

After Chandrayaan-3’s landing, the experiments: lunar quakes and water ice on Moon

Why in the News?

India has successfully made the Chandrayaan-3 landing on the lunar surface, becoming the first country to land on lunar south pole and 4^th country to land on moon (after the US, Soviet Russia and China).

The Mission Experiments:

Four experiments to be conducted by the Lander

1. RAMBHA: The Radio Anatomy of Moon Bound Hypersensitive ionosphere and Atmosphere
   • Studies the electrons and ions near the surface of the moon and its changes over time.
2. ChaSTE: Chandra’s Surface Thermo physical Experiment 
   • To study the thermal properties of the lunar surface near the polar region.
3. ILSA: Instrument for Lunar Seismic Activity 
   • Measures the lunar quakes near the landing site
   • To study the composition of the Moon’s crust and mantle.
4. LRA: LASER Retroreflector Array 
   • It is a passive experiment sent by NASA that acts as a target for lasers for very accurate measurements for future missions.

Two experiments to be conducted by the Rover

1. LIBS: LASER Induced Breakdown Spectroscope
   • To determine the chemical and mineral composition of the lunar surface.
2. APXS: Alpha Particle X-ray Spectrometer
   • To determine the composition of elements such as magnesium, aluminium, silicon, potassium, calcium, titanium, and iron in the lunar soil and rocks.

Discovery of water

1. The deep craters that remain in permanent darkness in the southern polar region of the Moon has high likelihood of having water-ice.
2. During Chandrayaan-1 mission,
   1. India’s Moon Impact Probe (MIP) was deliberately crashed on the lunar surface near the south pole enabled to study the concentration of water and hydroxyl molecules in the lunar atmosphere.
   2. mini-SAR payload helped to detect the subsurface deposits of water-ice in craters in the permanently shadowed regions near the south pole.
   3. Moon Mineralogy Mapper or M3 payload of NASA helped detect these molecules on the surface of the Moon.

Buried lava tubes

• Chandrayaan-1 detected an underground lava tube that can provide a safe environment for human habitation in the future.
• It can protect against hazardous radiation, small meteoric impacts, extreme temperatures, and dust storms on the surface of the Moon.

Magma ocean thesis

1. The Moon is believed to have been formed after an early piece of the Earth separated due to an impact. The energy generated by the impact is believed to have led to the melting of the Moon’s surface. This is called the magma ocean hypothesis.
2. The M3 payload on board Chandrayaan-1 picked up a specific type of lighter-density crystals on the surface of the Moon, which could be found on the surface only if it were liquid once.

Mapping of minerals

• CLASS X-ray Fluorescence experiment has mapped ~ 95% of the lunar surface in X-rays for the first time. X-ray spectrometers flown to the Moon in the past 50 years together have covered only less than 20% of the surface, according to ISRO.

A dynamic Moon

• Findings from the Chandrayaan-1 mission also showed that the Moon’s interior was dynamic and interacted with the exosphere, contrary to the belief that it was dormant.
• The terrain mapping camera found evidence of volcanic vent, lava pond, and lava channels as recent as 100 million years old, indicating recent volcanic activity. Measurements of carbon dioxide by the MIP also pointed towards de-gassing from the surface. This shows an interaction of the lunar surface with the exosphere even in the absence of impacts by meteors.