India's third Moon mission Chandrayaan 3 will deploy a lander and a rover at
a high latitude location of the Moon enabling us to carry out first ever
in-situ science investigations of such a pristine location that will
potentially improve our understanding on primary crust formation and subsequent
modification processes. The primary landing site (PLS), is situated at
69.367621 degS, 32.348126 degE. As a contingency, an alternate landing site
(ALS) was also selected at nearly the same latitude but nearly 450 km west to
PLS. In this work, a detailed study of the geomorphology, composition, and
temperature characteristics of ALS has been carried out using the best-ever
high resolution Chandrayaan 2 OHRC DEMs and Ortho images, datasets obtained
from Chandrayaan 1 and on-going Lunar Reconnaissance Orbiter. For understanding
the thermophysical behaviour, we used a well-established thermophysical model.
We found that the Chandrayaan 3 ALS is characterised by a smooth topography
with an elevated central part. The ALS is a scientifically interesting site
with a high possibility of sampling ejecta materials from Tycho and Moretus.
Based on the spectral and elemental analysis of the site, Fe is found to be
near approx. 4.8 wt.%, with Mg approx. 5 wt.%, and Ca approx. 11 wt.%.
Compositionally, ALS is similar to PLS with a highland soil composition.
Spatial and diurnal variability of around 40 K and 175 K has been observed in
the surface temperatures at ALS. Although belonging to similar location like
PLS, ALS showed reduced daytime temperatures and enhanced night-time
temperatures compared to PLS, indicating a terrain of distinctive
thermophysical characteristics. Like PLS, ALS is also seems to be an
interesting site for science investigations and Chandrayaan 3 is expected to
provide new insights into the understanding of lunar science even if it happens
to land in the alternate landing site.Comment: 13 pages, 7 figure