Vikram, in a first, records surface temperature variations from lunar south pole

All the six payloads – three on Vikram, two on Pragyan, the rover, and one on the propulsion module – were activated by Friday and the scientific experiments are under way.

In the first scientific finding from the Chandrayaan-3 mission, a payload on its lander, Vikram, has recorded a temperature drop of about 60 degrees Celsius from above the lunar surface to a depth of about 8 cm.

Temperature variations at different depths in the moon’s south polar region are being recorded for the first time, the Indian Space Research Organisation (Isro) said on Sunday.

The findings could enhance the understanding of heat flow patterns in the lunar polar regions and supplement blueprints for future habitats.

ChaSTE (Chandra’s Surface Thermophysical Experiment) is designed to measure the temperature profile of the lunar topsoil in the polar region to understand the thermal behaviour of the moon’s surface.

A graphical illustration of the recordings shows the temperature progressively dropping from above 50 degrees Celsius to -10 degrees Celsius with depth (from about 1 cm above the lunar surface to about 8 cm beneath the surface). “This is the first such profile for the lunar south pole. Detailed observations are under way,” Isro said.

The lunar topsoil is a poor thermal conductor which explains the drastic temperature drops as the ChaSTE probe goes deeper into the surface. A senior scientist familiar with the instrument’s configuration told DH that understanding these heat flow patterns is crucial for developing future habitats.

“This could also lead us to water-ice. If the location being probed now can itself throw up such low temperatures, at only 10 cm beneath the surface, there is a high possibility of finding water frozen beneath the craters,” the scientist said.

The payload comes with a temperature probe that has a controlled penetration mechanism and is fitted with 10 temperature sensors.

The penetration mechanism can go as deep as 10 cm beneath the lunar surface.

The instrument probes the surface through meticulously phased insertions to ensure minimal disturbance to the soil. It takes about four to five hours to reach 10 cm beneath the surface.

ChaSTE was developed by a team led by the Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram, in collaboration with the Physical Research Laboratory, Ahmedabad.

The lander module of Chandrayaan-3 touched down near the lunar south pole on August 23.