Moon’s surface patterns may be result of ‘plumbing system’

The famous flattened image across the moon’s surface - dubbed the Man in the Moon - may have been created by the moon’s plumbing system.

The famous flattened image across the Moon’s surface – long dubbed the Man in the Moon – may have been created by the Moon’s plumbing system.

The mystery behind the 2,900-kilometre-wide section of the Moon’s Procellarum basin has been a long-running puzzle among scientists who have previously claimed it may have been caused after a massive asteroid crash.

The latest research, published in the journal Nature, now suggests it may have been caused by a large plume of magma deep inside the Moon coming up towards the surface.

Using data obtained from Nasa’s Grail (Gravity Recovery and Interior Laboratory) mission, the research team from the Massachusetts Institute of Technology (MIT), the Colorado School of Mines and other institutions have created a high-resolution map of the Procellarum.

They found that its border is not circular, but polygonal and made up of sharp angles that could not have been created by a massive asteroid. They believe the angular outline was produced by giant tension cracks in the Moon’s crust as it cooled around an upwelling plume of hot material from the deep interior.

Maria Zuber, MIT’s vice president for research, says that as cracks occurred, they formed a “plumbing system” in the Moon’s crust through which magma could meander to the surface. Magma eventually filled the region’s smaller basins, creating what we see today as dark spots on the near side of the Moon. These are the features that have inspired the idea of a man in the Moon.

Ms Zuber, who is also Grail’s principal investigator, said: “A lot of things in science are really complicated, but I’ve always loved to answer simple questions.

“How many people have looked up at the moon and wondered what produced the pattern we see – let me tell you, I’ve wanted to solve that one.”

The map was created using twin probes that orbited the Moon from January to December 2012 and were used to determine where the lunar crust thickens and thins.

They found that the rim of the Procellarum region is composed of edges made up of 120-degree angles. An asteroid strike would create circular or elliptical craters and not these angular shapes, the team suggests.

They then went on to explore a theory that some time after the Moon formed and cooled, a large plume of molten material rose from the lunar interior, around where the Procellarum region is today.

The steep difference in temperature between the magma plume and the surrounding crust caused the surface to contract over time, creating a pattern of fractures that provided a chance for molten material to rise to the surface.

Further tests, created by modelling the region’s gravitational signal, matched data recorded by Grail and backs the idea that the Procellarum was caused by a magma plume and not an asteroid.

But the mystery of the Man in the Moon has still not been completely solved despite this latest theory, according to Ms Zuber.

She said: “How such a plume arose remains a mystery. It could be due to radioactive decay of heat-producing elements in the deep interior. Or, conceivably, a very early large impact triggered the plume. But in the latter case, all evidence for such an impact has been completely erased. People who thought that all this volcanism was related to a gigantic impact need to go back and think some more about that.” – PA