Distribution of Sodium on the Moon’s surface
- Scientists from Indian Space Research Organisation (ISRO) have mapped out the global distribution of sodium on the Moon’s surface.
- They used the CLASS instrument (Chandrayaan-2 large area soft X-ray spectrometer) carried by the second Indian Moon mission, Chandrayaan-2.
How was it done?
- This is the first effort to provide a global-scale measurement of sodium on the lunar surface using X-ray fluorescent spectra.
- Non-destructively analysing the composition of materials is a popular application for X-ray fluorescence.
- When the sun emits solar flares, the moon is exposed to a significant amount of X-ray radiation, which causes X-ray fluorescence.
- The CLASS counts the total amount of X-ray photons arriving from the moon and assesses their energy.
- The intensity is a measurement of how many atoms are present, and the energy of the photons reveals the number of atoms (for example, sodium atoms release X-ray photons of 1.04 keV).
- Rock samples were returned from earlier lunar trips like Apollo-11, Luna, and Chang’e-5.
- The sodium content of the rocks was properly measured in those missions.
- Apart from the trace amounts detected in lunar rocks, a recent analysis by the Chandrayaan group reveals that there is a thin veneer of sodium atoms that are weakly linked to the lunar surface (as mentioned earlier).
- When enough energy is provided to them by solar UV light and solar wind ions, these sodium atoms on the surface are released.
- This achievement by Indian Space Research Organization (ISRO), is a great step towards scientific exploration of lunar surfaces.
- The scientists of Indian Space Research Organization (ISRO) have stated that “As the solar cycle is in its ascending phase, we expect more solar flares that would ensure a larger coverage of all elements on the moon by CLASS at the highest spatial resolution ever”.
Source The Hindu