Imagine looking up to the sky every night just to see the Halloween orange and chimney red glow from dozens of volcanoes on the surface of the moon. According to a new research paper just published in Nature Geosciences, humans would be able to enjoy such a show in the future.
Using recent moonquake information gathered by the seismometers installed during the Apollo missions, NASA's Marshall Space Flight Center planetary Dr Renee Weber Project, says that about 30 per cent of the lunar mantle surrounding the moon's metallic core is molten. Weber, who is in charge of the the Lunar Mapping and modelling project, claims that this liquid lava is about 1200km and 1350km deep.
So why there are no active volcanoes now? The moon's surface is dead and, in fact, we know that the latest eruptions happened billions of years ago. Perhaps this means there will be future eruptions? A group of scientists led by Mirjam van Kan Parker and Wim van Westrenen from VU University Amsterdam, may have found the answer to these questions.
Since we can't access the lava, they solved the puzzle using an ingenious technique. First they got some samples from the 350kg of rocks brought back by the Apollo missions. Then they put those rocks under the same conditions in which that molten moon lava is: more than 45,000 bars of pressure and temperatures of about 1500C.
After creating this artificial lava, they used the European Synchrotron Radiation Facility in Grenoble to analyse it using powerful X-rays. With that data, they created a computer simulation which found out that the Moon's magma is very rich in titanium. This makes it way too heavy to flow into the surface. Lava needs to be lighter than its surroundings in order for it to erupt into the surface, but this is not the case.
According to van Westrenen, "after descending, magma formed from these near-surface rocks, very rich in titanium, and accumulated at the bottom of the mantle — a bit like an upside-down volcano. Today, the Moon is still cooling down, as are the melts in its interior." That solves the why there are no volcanoes questions. But what about the future?
In the distant future, the cooler and therefore solidifying melt will change in composition, likely making it less dense than its surroundings. This lighter magma could make its way again up to the surface forming an active volcano on the Moon — what a sight that would be!