Why in news?  ISRO releases graph of temperature variation of topsoil in lunar South Pole by ChaSTE

Highlights:

• The payload has a temperature probe equipped with a controlled penetration mechanism capable of reaching a depth of 10 cm beneath the surface.
• Operation is carried out by means of inserting a probe consisting of thermal sensors in to the lunar regolith using a motor based mechanism.
• ChaSTE is on board with Vikram Lander and Chandrayaan-3 probe showed 50°C difference between moon’s surface and 10 cm below

What is ChaSTE?

• Chandra’s Surface Thermo physical Experiment (ChaSTE) measures the temperature profile of the lunar topsoil around the South Pole, to understand the thermal behaviour of the moon’s surface.
• It aims at in-situ measurements of thermal conductivity and temperature profile on the lunar surface to derive the vertical temperature gradient up to a depth of 100 mm at the site of landing.
• It was developed jointly by the Physical Research Laboratory(PRL), Ahmedabad and the Space Physics Laboratory(SPL), VSSC, Trivandrum.
• The flight model for chandrayaan-2 has been delivered in 2017.