New Delhi: Chandrayaan-2, which has been hovering around the Moon since 2019, has mapped an abundance of sodium on the moon for the first time. The new findings provide an avenue to study surface-exosphere interaction on the moon that would aid development of similar models for mercury and other airless bodies in our solar system and beyond.
According to the Indian Space Research Organisation or Isro, the X-ray spectrometer ‘CLASS’ on the Chandrayaan-2 orbiter mapped an abundance of sodium on the moon for the first time.
Chandrayaan-1 X-ray Fluorescence Spectrometer (C1XS) detected sodium from its characteristic line in X-rays which opened up the possibility of mapping the amount of sodium on the Moon, Isro said in a statement.
Chandrayaan-2 Large Area Soft X-ray Spectrometer or CLASS, built at the UR Rao Satellite Centre of Isro, provides clean signatures of the sodium line thanks to its high sensitivity and performance, the space agency said.
A recent study found that a part of the signal could be arising from a thin veneer of sodium atoms weakly bound to the lunar grains. The sodium atoms can be nudged out of the surface by solar wind or ultraviolet radiation more easily if they were part of the lunar minerals.
Chandrayaan-2 also found a diurnal variation of the surface sodium that would explain the continuous supply of atoms to the exosphere, sustaining it. Besides, Sodium was found in the wispy atmosphere of the moon, a region so thin that the atoms there rarely meet.
This region, termed an ‘exosphere’, begins at the surface of the moon and extends several thousand kilometres merging into interplanetary space, Isro noted.
Chandrayaan-2, hovering in lunar orbit, had earlier discovered that the Moons ionosphere has a plasma density in the wake region, which is at least one order of magnitude more than what is present on the day side. The spacecraft has been studying the lunar surface ever since it arrived in orbit in 2019.
