Cracks in the surface of the Moon suggest that our nearest neighbour in space is getting smaller.Scientist believe that “like a deflating balloon, the satellite is contracting as its interior cools.”
The discovery was made after a probe captured images of unusual fault lines called ‘lobate scarps’ in the lunar highlands.Similar cracks were first seen in photos taken near the Moon’s equator by the Apollo astronauts.
Fourteen new lobate scarps have now been identified by the Lunar Reconnaissance Orbiter spacecraft, researchers reported in the journal Science.They were found mainly in the highlands, showing that the lines are globally distributed.
Experts believe the cracks were created by rupturing of the brittle lunar crust as the Moon shrank – a process that appears to be geologically recent.
Dr Thomas Watters, from the Smithsonian Institution in Washington DC said:
“One of the remarkable aspects of the lunar scarps is their apparent young age.Relatively young, globally distributed thrust faults show recent contraction of the whole Moon, likely due to cooling of the lunar interior.The amount of contraction is estimated to be about 100 metres in the recent past.”
During the Apollo space missions in the 1970s, astronauts detected a number of moonquakes – and Dr Watters now believes it is possible they emanated from the newly discovered faults.Lobate scarps have also been found on other planets in our solar system, including Mercury, where they are much larger.
Dr Watters added: “Lobate scarps on Mercury can be over a mile high and run for hundreds of miles“.