Score One for Hollow Moon Theory

It’s been a bit since I posted about the Hollow Moon Theory. For those who are unfamiliar, the theory is simple; the Moon is far older than the 4.3 Billion years the Earth and the Solar System are. Plus it’s artificial.

Enter the GRAIL probe.

A sneak peek at the first results from a NASA mission to measure the Moon’s gravitational field hints at a lunar crust that is only half as thick as once thought.

There were a few gasps among scientists in the audience at a 13 September seminar at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, as they took in the data revealed by Maria Zuber, principal investigator for NASA’s Gravity Recovery and Interior Laboratory (GRAIL) mission. Zuber, a planetary scientist at the Massachusetts Institute of Technology in Cambridge, showed a crisp, high-resolution gravitational map made with data collected by GRAIL’s twin spacecraft between March and June of this year.

“We are three to four times better in resolution compared to Kaguya and Lunar Prospector,” said Zuber, referring to two previous missions that mapped the Moon’s graviational field.  GRAIL’s results have not yet been published or released publicly by NASA, and Zuber was not at liberty to give an interview.

Yet her talk, and the thrilled reactions from those present at the seminar and others interviewed by Nature, suggest that GRAIL is poised to have a profound effect on scientists’ understanding of the origins and early evolution of the Moon when its results are released in the coming weeks.

GRAIL’s two probes, named Ebb and Flow by schoolchildren in a NASA competition, were launched in September 2011 (see ‘Twins to Probe Moon’s Heart’). The first probe began orbiting the Moon on 31 December 2011, with the second joining the next day. By March, they had begun detailed mapping. The two spacecraft exchange radio signals, recording fluctuations in their relative positions that are then used to reveal tiny accelerations and decelerations caused by variations in the Moon’s gravitational field. The average altitude of the primary mission was 55 kilometres —  much lower than the orbit used by the Gravity Recovery and Climate Experiment (GRACE), a similar gravity-mapping mission for Earth that has to fly higher to avoid atmospheric friction. Occasionally, the GRAIL operations team brought the craft lower than 20 kilometres to further improve the resolution of the data. “Nothing beats flying low,” says Zuber.

Zuber gave the packed auditorium a heads-up on three science results. The first is that the Moon’s crust seems to be thinner than thought. When lunar geologists first estimated the thickness of the Moon’s crust, using data from seismometers placed by the Apollo astronauts, they concluded that it was around 60 kilometres thick. Subsequent re-analyses of those data brought the estimate down to around 45 kilometres. Now, GRAIL’s results suggest that the crust’s average thickness is only 30 kilometres, says Zuber. ( emphasis mine )

Now, it could very well be that underneath that 30 klicks of crust is a different kind of rock and there is nothing artificial at all.

But the Moon has stories that span generations of things flashing across its surface, smoke appearing, tales of spaceships and aliens who told NASA to keep mankind’s filthy paws off from it.

Maybe this is scientific validation of the theory?

Tandem satellites probe the Moon’s interior

Hat tip to the Daily Grail.