A strange 'gel-like' substance has been discovered on the far side of the moon by a lunar rover sent by China's space agency.

The Yutu-2 rover, which landed on the far side of the moon in January of this year, found the substance last month but news of the discovery has just been made public.

The rover, part of China's Chang'e-4 lunar mission, discovered the substance in a crater just before it was set to power down for its usual midday 'nap'.

A strange 'gel-like' substance has been discovered in a crater (pictured) on the far side of the moon by the Yutu-2 lunar rover sent by China's space agency

A team member looking at the rover's main camera spotted the small crater, which appeared to contain material with a colour unlike the surrounding lunar surface, Space.com reported.

Having seen the images, lunar scientists decided to postpone plans to send Yutu-2 further west and instead ordered the rover to check the strange material.

The rover, which is on the moon with the Chang'e-4 lunar probe, carefully approached the crater and then targeted the strangely-coloured material.

The Yutu-2 rover, which landed on the far side of the moon in January of this year, found the substance last month but news of the discovery has just been made public

It was then that the scientists made the strange discovery, although they have so far only said that the substance was 'gel-like' and an 'unusual colour'.

One possible theory which was suggested by researchers not involved with the mission is that the substance is melted glass created from meteorites striking the surface of the moon.

China's space agency previously said the current mission 'lifted the mysterious veil' from the far side of the moon, which is never seen from Earth, and 'opened a new chapter in human lunar exploration'.

A team member looking at the rover's main camera spotted the small crater, which appeared to contain material with a colour unlike the surrounding lunar surface. Above: The tracks made by Yutu-2 as it approached the crater

Having seen the images, lunar scientists decided to postpone plans to send Yutu-2 further west and instead ordered the rover to check the strange material. The rover, which is on the moon with the Chang'e-4 lunar probe, carefully approached the crater and then targeted the strangely-coloured material

Because the space craft is solar powered, it has to switch off during a lunar night on the moon, during which there will be no sunlight.

The temperature on a lunar night is about -180°C (-292°F) and can get high during the day, where 'insulating' components like the gold coloured layers outside the lander and rover keep them cool.

Results of experiments from the mission could lead to new understandings of the challenges faced by settlers who may one day colonise our natural satellite.

The mission is formed of three basic parts - the rover, the lander and the relay satellite. They will work in unison to study, analyse and send information back to the scientists on Earth