| Name: | Ashish Devaraj |
| Affiliation: | CHRIST (Deemed to be University) |
| Conference ID : | ASI2024_364 |
| Title : | Sodium in the Lunar Exosphere and Surface: First Results from Vainu Bappu Telescope and Chandrayaan-2 |
| Authors : | A. Devaraj1, S. Narendranath2, T. Sivarani3, S. S. Kartha1 and B. Mathew1 |
| Authors Affiliation: | 1. Department of Physics and Electronics, CHRIST (Deemed to be University), Bengaluru - 560029, India
2. Space Astronomy Group, U R Rao Satellite Centre, ISRO, Bengaluru - 560017, India
3. Indian Institute of Astrophysics, Bengaluru - 560034, India |
| Mode of Presentation: | Poster |
| Abstract Category : | Sun, Solar System, Exoplanets, and Astrobiology |
| Abstract : | Our Moon hosts a sparse atmosphere called a Surface Boundary Exosphere (SBE). Previous research has unveiled the presence of noble gases and the moderately volatile element Sodium (Na) in the lunar SBE. Sodium in the lunar exosphere is primarily sourced from the lunar surface. It is enriched through several physical processes, including ion sputtering from the solar wind, photodesorption, thermal desorption, and micrometeorite impact vaporisation. The specific contribution of each of these processes and their dependence on the surface abundance of sodium in the enrichment of the lunar sodium exosphere remains a topic of ongoing research, and we aim to address this problem by combining ground-based observations with surface abundance data from the Chandrayaan-2 Large Area Soft X-ray Spectrometer (CLASS) onboard Chandrayaan-2. We successfully observed the lunar exosphere using the high-resolution Echelle spectrometer on the 2.34-meter Vainu Bappu Telescope (VBT) for the first time during the full Moon phase in March and April 2022. Extensive sampling over the eastern equatorial and south pole regions covered the lunar disk and various tangential altitudes above the lunar limb. The NaI D1 and D2 emission lines at 5895.93 Å and 5889.96 Å were identified in the exosphere by meticulously analysing the gathered spectra. These detections provided insights into the spatial variation of sodium in the lunar exosphere. By comparing these observations with the Na abundance data obtained from CLASS, we aim to study the physical processes governing Na release from the lunar surface to the SBE. The initial findings from this study and their implications will be presented. |
