Chandrayaan-2 Discovers Argon Gas In Moon's Exosphere, Offering Exciting Insights
India's Chandrayaan-2 has made some discoveries about the Moon. With Chandrayaan-3 set to take off later this year, its predecessor is still making observations about Moon's surface.
Chandra’s Atmospheric Composition Explorer-2 (CHACE-2) instrument onboard the Chandrayaan-2 has found Argon-40 in the lunar exosphere - the upper atmosphere of Moon situated beyond areas it was known to exist, ISRO statement said.
What does this mean? This observation could provide insights into how lunar exospheric species and processes unfold on the Moon.
In turn, it could help scientists understand the composition of lunar surface. The CHACE-2 was able to spot the presence of Argon in the equatorial and mid-latitude areas of the Moon.
Why this discovery matters
Mind you, this isn't the first time that Argon-40 has been detected on the Moon. But previous observations were limited to near-equatorial regions as seen by the Apollo-17 mission. “Though, Argon-40 (Ar-40) is known to exist in the lunar exosphere, the knowledge on its distribution at higher latitudes is lacking. For the first time, Chandra’s Atmospheric Composition Explorer-2 experiment aboard Chandrayaan-2 orbiter has continuously observed Ar-40 in latitude range of -60 to +60 degrees,” according to the study published in the scientific journal Geophysical Research Letters.
Argon-40 is an inert, colourless and odourless element categorised as a noble gas. ISRO claims that once formed, the gas diffuses with inter-granular space and then runs upward to the lunar exosphere.
The study was led by M.B. Dhanya of the Vikram Sarabhai Space Centre and noted an increase in the density of Argon-40 near the sunrise terminator, a decrease along the dayside, a secondary peak near the sunset terminator, and a night-side minimum.
Their biggest discovery was that the density of Argon-40 along solar longitudes is similar to that of low latitude regions - even with differences in temperature and topography.
Sinha, A. (2022, March 8). Chandrayaan-2 orbiter makes new discovery about distribution of gas in moon’s atmosphere. The Indian Express.
Desk, I. T. W. (2022, March 8). Chandrayaan-2 makes exciting new discovery below Moon’s surface. India Today.