Researchers in India have been unable to communicate with the country's unmanned lunar probe, since it entered a dormant state earlier this month. Chandrayaan-3 became the first probe in history to successfully land near the lunar south pole in August.

A rover attached to the lander went exploring after the probe touched down. It spent two weeks examining soil and rock components on the surface.

The solar-powered vehicle was put into 'sleep mode' when night fell on the moon. The duration of both a lunar day and night is two weeks.

The Indian Space Research Organisation expected the probe to wake up when the sun came out last Friday. But it says it still cannot make contact with Chandrayaan-3.

The temperature near the moon's south pole can drop to minus 150 degrees Celsius or lower after sunset. Observers say the probe may not have been able to withstand the extremely harsh environment.

ISRO believes it may be extremely difficult for the vehicle to resume operations. But the organization has praised the probe's achievements. It says Chandrayaan-3 will remain on the moon forever as India's "lunar ambassador," if it does not wake up.