It's Cheese, Gromit, But Not As We Know It!

As a child asked what I wanted to do when I grew up, I would ignore the likelihood that my asthma, 5'1 height and lack of army training would probably prevent my dream and reply 'Astronaut'. Well twelve lucky, strong-lunged and tall men got to live out my dream and visit the Moon. Now, over forty years on, the Apollo missions are once again proving their scientific worth and are back in the forefront of scientific minds as new analytical techniques applied to  seismic data taken from the moon during Apollo has discovered the Moon has a liquid core like our Earth. 

In the final Apollo mission (the only geologist astronaut), Harrison Schmitt, collected a pristine and beautiful moon rock sample, Troctolite 7653. Full of milky white and dark green crystals, an analysis of this sample showed evidence of magnetic alignment, and the possibility of a liquid Moon core. It can now be compared with data collected between 1962 and 1977 when the Apollo missions deployed four seismic stations which recorded seismic tremors beneath the Moon's surface.

Dr Schmitt poses with the American flag, with the Earth in the background.

 The new research shows that the core seems to have both a solid and a liquid section, similar to our own Earth, however it also contains a partially melted section which our own planet is missing containing both large lumps of rock as well as magma. Dr Renee Weber (a very accomplished woman in science and the project scientist for the Lunar Mapping and Modeling Project) and her colleagues analyzed this data to find the moon has a core of 330Km diameter, which is still liquid even 4.5 Billion years after the moon formed! She is currently involved in, what is now a very important, proposal to send seismic data instruments back to the Moon. Although, sending modern technology to the Moon surface has no guarantee of producing better results. The rarity of Moonquakes means data is sparse, whilst the cracked and broken surface means signals are masked by noise, hence why computers of the seventies were unable to decode the signals they received then. 

The Moon's layers

 Up until now the topography and mineralogical composition of the moons surface was well understood, but it's interior remained in doubt. If the Moon did indeed form when a Mars sized object impacted the partially molten Early Earth then it stands to reason it would contain various heavy elements and light elements which would separate out into a core, mantle and crust. Weber understands the implications of her discovery. "If we have any hope of determining once and for all how the moon formed then we need to understand it's structure completely." 

It seems Gromit will need to find some more evidence before we all agree with his theory that the Moon is in fact made from cheese.