With the aid of the Chandrayaan-2 mission’s CLASS instrument (Chandrayaan-2 large area soft X-ray spectrometer), ISRO scientists have determined the global distribution of sodium on the Moon’s surface.
- This is the first attempt to use X-ray fluorescence spectra to obtain a global-scale assessment of sodium on the lunar surface.
GS III: Science and technology
Dimensions of the Article:
- About Chandrayaan-2
- What is X-Ray Fluorescence?
- How is it related to the history of moon?
- Chandrayaan-2 is an integrated 3-in-1 spacecraft of around 3,877 kg comprising of an Orbiter of the Moon, Vikram (after Vikram Sarabhai) the lander and Pragyan (wisdom) the rover, all equipped with scientific instruments to study the moon.
- The Orbiter will orbit from 100 km away, while the Lander and Rover modules will separate and make a soft-landing on the surface.
- Lander (Vikram) will remain stationary after touching down, will mainly study the moon’s atmosphere.
- It will also look out for seismic activity.
- Rover (Pragyan): Once on the Moon, the Rover, a six-wheeled solar-powered vehicle, will detach itself and slowly crawl on the surface, making observations and collecting data.
- It will study the composition of the surface near the lunar landing site, and determine the abundance of various elements.
- Orbiter: While the Lander and Rover are designed to work for only 14 days (1 lunar day), the Orbiter, a 2,379-kg spacecraft with seven instruments on board, would remain in orbit for a year.
- It is equipped with different kinds of cameras to create high-resolution three-dimensional maps of the surface.
- It will study the mineral composition on the moon and the lunar atmosphere, and also to assess the abundance of water.
- The mission sequence involves meticulous planning of series of Earthbound manoeuvres, trans-lunar injections, series of lunar burns, lander separation, lander descent, and touchdown and subsequent rover rolling out of the lander on the Moon surface.
What is X-Ray Fluorescence?
- It is frequently used to non-destructively research the composition of materials.
- 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 atom (for example, sodium atoms release X-ray photons of 1.04 keV).
How is it related to the history of moon?
- Sodium can be used as a tracer of the volatile history of the moon.
- When compared to Earth, the moon is significantly depleted of volatile elements such as sodium.
- The amount of volatiles on the moon today can be used to test formation scenarios of the Earth-Moon system.
Source: The Hindu